PLACE IN RETURN BOX to remove this checkout from your record. TO AVOID FINES return on or before date due. .apmw - ABSTRACT / I NEVE STUDIES ON THE JUNEAU ICEFIELD, ALASKA, 1961 WITH SPECIAL REFERENCE TO GLACIO-HYDROLOGY ON THE LEMON GLACIER By Edward C. Andress A detailed abstract can be round in Chaper V, pages 76 - 81, under the title, SUMMARY AND INTEGRATION OF RESULTS. Owing to the broad and varied scope and significance of this dissertation, a chaper summarizing and integrating the results is necessary. Due to the same causes an abstract would tend to be quite comprehensive, indeed very similar to the summary. Therefore, in the interest of avoiding repeti- tion, the author has taken the liberty of designating Chapter V as the abstract in addition to its function as the summary. NEVE STUDIES ON THE JUNEAU ICEFIELD, ALASKA, 1961 WITH SPECIAL REFERENCE TO GLACIO-HYDROLOGY ON THE LEMON GLACIER BY. J x.f' 1. u“ Edward C, Andreas A.THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Geology 1962 3 231?? 0/3/93 PREFACE The following study was conducted as a part of the in- structional field program of the Glaciological Instituhg of the Department of Geology at Michigan State University, in cooperation with the Juneau Icefield Research Program of the Foundation for Glacier Research, Seattle, Washington. The author is indebted to the Glaciological Institute and the Foundation for Glacier Research for providing the oppor- tunity and means by which this study was carried out. Compilation of the data would have been impossible with- out the generous cooperation and aid of Mr. Ralph E. Marsh of the U.S. Geological Survey Water Resources Division, Juneau office, Mr. Joseph Bower and Mr. C. E. Watson of the U.S. Weather Bureau,Juneau and Anchorage offices, and the members of the 1961 J.I.R.P. expedition...especially Mr. James H. Anderson, Mr. Douglas K. Bingham, Mr. Theodore F. Freers, Dr. Theodore R. Haley, Mr. Walter B. Lockwood, Jr., Mr. Jon Lundberg, Dr. Maynard M. Miller, Mr. Michael Porter, and Mr. Barry W. Prather. The author wishes to express the deepest appreciation to his chairman, Professor Maynard M. Miller, for his con- stant guidance and encouragement during the field work and throughout the preparation of this dissertation. Further appreciation is extended for his helpful suggestions with respect to integrating the present study with details of previous research activities on the Juneau Icefield. Par- ticularly valued is his generosity in making available 11 iii unpublished data and interpretations from some of his own investigations in this area. The writer would also like to thank Professors William J. Hinze and James W. Trow for serving on his committee. In addition, the author is grateful to his wife, Claire, for her patience and efficiency in typing the manuscript. TABLE OF CONTENTS I. PURPOSE AND PHYSICAL SETTING...................... II. MAIN ICEFIELD RELATIONSHIPS....................... A. B. Orographic, Area, and Elevation Factors....... GlaOIOthermal Conditions.................o...o l. EleCtro-Thermal Boringoocooooc000000000000 2. 1961 Thermistor Measurements and Englacial Temperature Conditions.......... Ablaticn and Melt-Water PerC01at10nooooooooooo 1. Main CrGStal NéVéooooooooooooooooooooooooo 2. Main Lower NéVé........................... 3. MOde Of PerCOIQtionooooo0.0000000000000000 Firn Stratigraphy and StrUCturGQOOoooooooooooo 1. Main Creatal Firn-PaCkoooooocooooooocoo... a. Primary Stratificationoooooo00000000000 be Den51ty DeterMinationooo00000000000000. c. Secondary Englacial Structures......... 20 Main Lower Firn’PaCkoococ00.000.000.000... a. Primary Stratificationoooo0000000000000 b. secondary Englacial Structures......... G18C10-Chemical Analysescooooooo0.000.000.0000 1. Significant Icefield variationSooooooooooo a. Areal Distribution of Salines.......... b. Depth Distribution of Salines and Interpretation 0! AnomalieSoooooooooooo 2. Climatologic Implications................. Interpretations of the Crestal Névé Thermal Bore-H016 Dataooooooooooo00.000000000000000... G18010'C11mat0108y00000000000000000000.0000... 1. Temperature and Precipitation Measurements. 2. Duration of Sunshine Records............... iv Page -q o~ #? #7 1'0 15 15 17 21 22 23 2 28 28 29 30 31 31 32 35 37 ho ho A3 III. IV. V.. VI. VII. VIII. IX. 3. 8013? Radiation RecordS................... h. Lemon Glacier Meteorology................. H. Composite Considerations...................... GLACIO-HYDROLOGIC INVESTIGATIONS ON THE LEMON GLACIER...O0COOOOOOOOOOO...0.0.0.00000000... A. The Lemon Glacier Problem..................... 1. Total Runoff vs. Refrozen Percolation..... 2. Areametric Relationships.................. 3. Meteorologic Implications................. A. Discharge Statistics...................... B. Special Considerations........................ 1. Potential Effects of Climatic Change...... 2. Hydrograph Anomalies...................... 3. Periodic Large—Scale Floods............... OTHER GEOMORIHIC CONSIDERATIONS................... A. Potential Glacier Reservoir Capacity.......... B. Practical Aspects of Erosion and Sedimentation................................. C. Water and Hydro-Power Projects................ SUMMARY AND INTEGRATION OF RESULTS................ A. Brief of the Névé Investigations.............. B. Brief of the Glac io-Hydrologic Investigations.. C. Review of Practical Glac iologic Considmaticns... SIGNIFICANCE OF THE 1961 STUDY.................... SUGGESTIONS FOR FURTHER INVESTIGATION............. REFERENCES CITED................L.............;... ILLUSTRATIONS..................................... Page A3 A3 Re 51 51 51 52 S3 57 sh 6h 66 68 71 71 72 7h 76 76 78 80 82 8h 88 9O vi Page X. APPENDED DIXTAOO0.00.00.000000000000000000000000000 117 XI. GLOSSARYOOOOOOOOOOOOO0.000.00000000000000000000... 172 Figure 1. 9. IO. 11. 12. 13. LIST OF ILLUSTRATIONS Sketch map of Juneau Icefield and Vicinity S.E. Alaska, showing the Main Field Sites (19615, and the Coastal Meteorologic Stations Located at An- nex Creek, Juneau City, Mt. Juneau, and Juneau Airport000000000000oo00000009000000000000000000000 Map of Taku Glacier System Showing 1961 Névé Investigation Sites and Field Research Station LocationSCIIOOOOO00.00.00OOOOOOOOOOOOOOOOOOCOOOOOO Detail Of EleCtro-Thermic GlaCier Dr11100000000000 Comparative Profiles of Thermal Bore-Rate, Englacial Temperature and Density in the Coastal Névé, Taku-Llewellyn Glacier System, Juneau Icefield” AlaSkaOOOOOO0.0000...OOOOOOOOOOOOOOOOOOO S.I.P.R.E. S-Inch O.D. Hand Auger and Core samplerOO0.0.0.0.0...0.000.000.0000...0.000.000... Wheatstone Bridge, Selector Swiufliand Thermistor Glacio-Thermal Cables Used on the Juneau Icefield RasearCh Program, 1960 and 19610000000000000000000 Total Gross Ablation on Lower Taku Névé, 25 July - 26 August 196l0.0...°°...°O.....°..........P...... Across-Glacier Ablation Profile Showing Relative Gross Ablation in Eastern Third of Lower Nevé, Sumer’ 19610000000000.00000000000000000000000000. Comparison of Daily Precipitation, Temperature and Ablation in Camp 10 Sector of the Lower Neva, Juneau Icefield, Summer, 1961000000000000000000000 wall Profile Showing Firn Stratigraphy and Percolation Pan Positions in the 1960—61 CreStal Firn—PaCk at Camp 8A, 19610000000000000000 Comparative Stratigraphy of Camps 8A and 19A 60-Foot Bore-Holes, Crestal Néve, Taku-Llewellyn GlaCier SyStem, September, 19610000000000000000000 Annual Accumulation and Stratigraphic Sequence in the Crestal Névé as Revealed by Crevasse Wall Measurements, at Site 8D, S700-Foot Level, Taku GlaCIGr SYStem, AlaSka, 19610000000000000000000000 Areal Distribution of NaCl Content on Late- Summer Névé Surfaces of the Juneau Icefield, vii Page 9h 95 95 96 97 98 99 ICO 101 Figure 1h. 15. 16. 17. 18. 19. 20. 21. 22. 23. 2h. 25. 26.‘ 2?. viii AlaSka, 1960-61.00.00.O...OOOOOOOOOOOOOOOOOOOOOOOO Variation of NaCl Content in Snow, Firn, and Deep Ice at Camp 10B on the Lower Névé, Juneau Icefield, 1950-51..........................0...... NaCl Content in Firn-Pack of Crestal Nave at Camps 8A and 19A on the Juneau Icefield, 1961..... Comparative Mean Daily Temperatures on the Lower Névé, Taku Glacier, and at Juneau City, Juneau Airport, and Annex Creek, April—October, '19610000000000000000000000000000000000000000000000 Radiosonde Mean Monthly Temperatures Recorded at Juneau Air ort at the Elevation of Camp 10, (3900 Feet), 19M '53000000000000000000000000000000000000 Comparative Histograms of Daily Precipitation for the Juneau Coastal Stations, Taku District, April- OCtOber, 19610000000000000000000000000000000000000 Daily Precipitation at Mt. Juneau Site, Elevation 3576 Feet, Covering Period July-September, 1961... Comparative Mean Monthly Temperature and Precipi- tation Curves for the Juneau Coastal Stations, 1951’610000300000000000000000000000000000000000000 Comparative Annual and January Means of Temper- ature; Showing ll-Year Annual and January Running Me'an Curves for the Juneau Coastal Stations, 19110-61. Comparative Annual and ll-Year Running Means of Precipation at the Juneau Coastal Stations, l9hO-6l. Lemon Creek Mean Monthly Discharge Rates at Gla- cier Terminus Gauging Site, for Period 1951-61, Juneau Icefield, A133k3000000000000000000000000000 Lemon Creek Mean Annual Discharge Rates, Juneau, Alaska, for PGPIOd 1951-61000000000000000000000000 Comparative Curves of Lemon Creek Maximum and Minimum Mean Annual Discharge Rates, Juneau Ice— field, AlaSka, for Interval 1952-61000050000000000 Lemon Creek Mean Daily Discharge Rate During Ablation Season 1961, Juneau Icefield, Alaska..... Juneau, Alaska B-1 and B-2 Quadrangles (1:63,360) Showing the Lemon Glacier, the Boundary of Its Drainage Basin, and the Lemon Creek Gauging Site.. Page 102 103 101, 105 me 107 108 109 110 111 112 113 11h 115 116 LIST OF APPENDED DATA Appendix Page 8. 9. 10. ll. 12. 13. 1h. 15. Glacio-Thermal Records Camp 8A - Thermal Bore Drilling Rate Readings, 1961..OOOOOCOOOOOCOOOOOOOO0..OOOOOOOOOOOOOOOOOOOOO Camp 8A - Thermistor Measurements, 1961 - 151' Bore-H01900000000000000000000000000000000000000000 Camp 8A - Thermistor Measurements, 1961 - 60' Bore-H016......................................... Camp 19A - Thermistor Measurements, 1961 - 60' Bore-HOIGOOOOOOOO00......0.0.00.0OOOOOOOOOOOOOOOOO Camp 88 - Thermistor Measurements, 1960 - 30' Bore-HOlGOOOOOOOOOOO000.00.00.00.00000000COOOOOOOO Site 8X - Thermistor Measurements, 1958 - 58' Bore-HOlGOOOOOOO0.0.0.0....OOOOOOOOO‘OOOOOOOOOOOOOO Site 8Y - Thermistor Measurements, 1958 - 90' Bore-H01e00000000000000000000000000000000000000000 Ablation Records Camp 8A - Daily Melt-Water Percolation Record, 1961. Camp 8A - Ablation Measurements, 196l............. Camp 10 — Ablation Measurements, 1961............. Camp 9 - Ablation Measurements, 1961.............. Firn Accumulation Records lS-Year Firn-Pack Accumulation Statistics for the Crestal Névé, Juneau Icefield, 19u6— 61............ Annual Primary Stratification on the Crestal Neva as Measured in 1960-610000000000000000000000000000 Annual Primary Stratification Statistics for the Intermediate Neve as Measured in 1960- 61.......... Annual Primary Stratification Statistics for the Level 3650-Foot Surface on the Lower Névé as MeaSured in 1950, 1958, and l960—61............... ix 118 125 128 130 131 132 133 13h 135 136 137 138 139 1h0 1&1 Appendix 16. 17. 18. 19. 20. 21. 22. 23. 2h. 25. 26. 27. 28. 29. 30. 31. 32. Firn-Pack Statistics for the Gilkey Neva, Site 19A, 6500-Foot Level Surface North of Mt. ogilv1e, 1961.00.00.000000000000000000000000000000 Firn Density Records Camp 8A - Firn Densit Measurements(S.I.P.R.E. Corer), September, 19 1000000000000000000000000000 Camp 8A - Firn Density Measurements (500 cc. Hand Corer), September 196100000000000000000000000 Camp 9 - Firn Density Measurements, August,l96l... Glacio-Chemical Records Juneau Icefield Saline Content Record, 1960-61.... Meteorologic Records Camp 8 - Daily Temperature and Precipitation Record, 1961......OCOCOCOCOOC.00...00......0...... Camp 8A - Daily Temperature and Precipitation Record, 196100000000000000000000000000000000000000 Camp9 - Daily Temperature and Precipitation Record, 196100000000000000000000000000000000000000 Camp 10 - Daily Temperature and Precipitation Record, 19610.00...0000......OOOOOOOCOOOOOOOOOCOOO Camp 8 - Duration of Sunshine Record, l96l........ Camp 10 - Daily Peak Solar Radiation Record, 1961. Mt. Juneau Daily Precipitation Record, 1961....... Annex Creek Daily Temperature and Precipitation Record, 196100000000000000000000000000000000000000 Juneau Daily Temperature and Precipitation Record, 1961.00.00...O0......O0.0.0.0000...OOOOOOOOOOOOOOC Juneau Airport Daily Temperature and Precipitation Record, 196100000000000000000000000000000000000000 Mean Monthly Temperature and Precipitation Record for Annex Creek, 1951'6100000000000000000000000000 Mean Monthly Temperature and Precipitation Record for Juneau, 1951-610000000OOOOOOOOOOOOO0.00.0.0... Page 1&2 1&3 1AA 1&5 116 1h? 1&9 151 15,3 155 156 157 158 160 162 16k 165 xi Appendix Page 33. Mean Monthly Temperature and Precipitation Record for Juneau Airport, 1951-61....................... 166 3A. Mean January and Mean Annual Temperature Record for Annex Creek, Juneau, and Juneau Airport, 19u0-61000000OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO 167 35. Mean Annual Precipitation Record for Annex Creek, Juneau, and Juneau Airport, l9hO-6l............... 168 Hydrologic Records 36. Lemon Creek Mean Monthly Discharge Record, 1951-61. 169 37. Lemon Creek Mean Annual, and.Mean Annual Maximum and Minimum Discharge Record, l952-61................. 170 38. Lemon Creek Mean Daily Discharge Record, 1961..... 171 1. PURPOSE AND PHYSICAL SETTING, The following study is inter-disciplinary in scope in— volving the fields of glaciology, meteorology, and hydrolo- gy. As suggested by the title the problem is two-fold. The first is concerned with the main accumulation sector of the Juneau Icefield in Southeastern Alaska (Fig. 1). In this there are three prime nourishment zones with mean elevations of 3900 feet, A600 feet, and 5900 feet. A fourth lesser plateau lies at a mean elevation of 6500 feet. All are on the main southerly draining outlet of the Juneau Icefield and as such comprise the névé of the Taku Glacier (Fig. 2). The existence of the fourth plateau was recognized in the summer of 1961, however time and logistic limitations in this field season precluded more than preliminary recon- naissance assessment of its extent and character. Emphasis in this study is, therefore, on the main crestal névé at 5900 feet where the nature and magnitude of propagated surface water and the influence of subsurface glaciothermal conditions are investigated, with special attention given to the problem of melt-water percolation and the genesis of secondary stratigraphic structures in the firn-pack. The basic purposes in this aspect of the study are to delineate more precisely than heretofore, the glaciothermal character of the main névés of the Juneau Icefield; and to outline the effects on the glacio-hydrologic budget which are occasion- ed by factors of elevation, geographic position, and associ- ated climatic conditions. The second aim is closely inter- related with the first in that it concerns investigation of factors producing runoff from the lowermost névé in the vi- cinity of the regional nave-line, in contrast to the upper- most névé where conditions opposing runoff are involved. Two months were spent on the Juneau Icefield in the summer of 1961 gathering control data for this study. Other statistics embracing the full year of 1961 are also used, both from the Taku Glacier system and the adjoining Lemon Glacierl (Fig. l). The Lemon Glacier lies southwest of the Taku Glacier system and has an area of approximately 7 square miles. This glacier, however, comprises a totally separate drainage system with a well—delineated catchment basin (12.1 square miles) not infiltrated by drainage from any other area. This circumstance lends itself to quanti- tative study of the effects of climate on the glacier, par- ticularly with respect to hydrologic consequences. The névé of the Lemon Glacier corresponds to the lower (3900-foot) névé on the main icefield. To some extent this permits extrapolation of data from the Taku system. Ten years of pertinent hydrologic reports from a stream gauging site at the glacier terminus on Lemon Creek are in hand. These have been made available to the author by the regional 1. In this dissertation it was found to be simpler and less cumbersome to use the term "Lemon Glacier", rather than "Lemon Creek Glacier" as it is sometimes called. The word "Creek" is restricted to the stream (Lemon Creek) 1t861f0 3 office of the U.S. Geological Survey in Juneau, Alaska. U.S. Weather Bureau climatologic reports and icefield records of the Juneau Icefield Research Program embracing the last de- cade provide further statistics for analysis of the glacio- hydrologic problem. Although the stream-gauge data are for the Lemon. Glacier only, the results can be significant with respect to regime considerations for the icefield as a whole. In view of this broader implication the results of the study and related statistics over the past 10 years are tab- ulated not only to support the conclusions drawn, but to make them available in summary form for future reference in other investigations of the long-term Juneau Icefield Re- search Program. To render the data most useful for further evaluations beyond the scope of the present purpose, special care has been taken in their compilation. Also in the in- terest of future perspectives the author's aim has been to veer in the direction of conservatism in the interpretations. II. M_A_IN ICEFIELD RELATIONSHQS The first consideration is the geographic-orographic relationship between areas investigated on the main branch of the Juneau Icefield. Following this the relationship of Lemon Glacier will be considered. Also to be examined are differences in the ablation-accumulation ratio and in the nature of glaciothermal conditions, as well as related aspects of surface water propagation, the transmission and storage of unfrozen water, firn density, stratigraphy, and salinity, and, of course, pertinent factors in the basic glacio-meteorology of the icefield as a whole. A. Orogrgphic, Area, and Elevation Factors In general, the nevés critical to this study are wide and flattish with surfaces gently sloping toward the mari-0 time flank of the Alaskan Boundary Range and, specifically, toward the central lower branch of the Taku Glacier system. The areal configuration is also relatively simple (Fig. 2). There are a number of broad platforms separated by slightly steeper zones of increased crevassing. At a mean gradient of 2.5 percent, however, they grade into each other almost imperceptibly and, hence, may be considered as continous. With the mean névé-line close to 3200 feet, the zone of nourishment extends from this level to that of the crest of the uppermost plateau...i.e. close to 7000 feet. The eleva- tion range is thus about 3800 feet. Essentially, there are two prime névés which will hereafter be referred to as the lower (maritime) and the crestal (or upper) névés. The elevation range of the lower néve extends between 32001 and 5000 feet; and the crestal nevé between 5000 and 6500 feet. The lower neve comprises approximately 110 square miles of the overall area in the Taku Glacier system; with the crestal névé occupying about 100 square miles. About 20 square miles of the glacier surface lies in the zone of dissipation below the névé-line. The two main nevés cited above are separated geographically by'a narrow section of the north branch of the Taku Glacier (mean elev. A600 feet) in the vicinity of Camp 9 (v. Fig. 1). As has been shown by Miller (1956) any significan changes or shifts in positive regime from the lower prime névé to the crestal, or vice versa, can have important bearing on the subsequent mass behavior of the main outlet glacier below the nave-line. In turn, measurements and trends found at the two sets of re- search sites, 8A-8B (5900 feet) and lOA-lOB (3650 feet), may be considered as representative of conditions at these re- spective névés. With the total area of the Taku Glacier system being close to 230 square miles, the accumulator-dissipator ratio is roughly 10 to l. In.comparison, the Lemon Glacier, with a slightly higher mean névé-line (approximately 3300 feet), 1. It is noted, however, that the semi-permanent ngvé-iin. on the Taku Glacier in 1961 rested at or slightly below 3000 feet. Its 1961 late-summer position on the Lemon Glacier was 3100 feet. has a total area of only 7 square miles. Thus, its accumu- lator-dissipator ratio under present conditions is about 5 to 1. Since the mean elevation of the Lemon Névé is at AOOO feet, with an upper limit in the vicinity of 5200 feet, it is subjected to climatologic conditions comparable to those of the lower maritime have of the main icefield. Its gradi- ent is slightly steeper, however, (approximately no) and its terminus lies at 1500 feet rather than at sea level. Also, it is much more confined in an orOgraphic setting of more mountainous character and its geographic position is some- what more maritime, factors which explain the slightly high- er néve-line which has been cited (v. footnote on P. 5). B. Glaciothermal Conditions 9 In the sub-surface investigation of the crestal névé both hand auger and thermal drilling equipment were used for the insertion of temperature-sensing cables. With these, englacial temperatures were measured, upon which determina- tion of the geophysical character of the upper nevé was made close to 6000 feet on the Taku-Llewellyn divide. Similar equipment was employed in the higher néve zone (6500 feet) northeast of Mt. Ogilvie (Fig. 2). This highest névé, which is a distinct unit in itself, requires distinction from the main crestal néve, and so W111 hereafter be referred to as the Gilkey Nevé. The results from each of these locales will be compared with the known temperature conditions found in the ice and firn of the lower névé which, as has already 7 been pointed out, is geophysically comparable to the Lemon Glacier Nevé. 1. Electra-Thermal Boring At Camp 8A on the névé at an elevation of 5950 feet (Fig. 2), an electro-thermal boring rig was used to pene- trate the firn to a depth of 151 feet. This drill was of a design previously used for investigation of the thermal character of the summit glaciers on Mount Rainier (Miller, 1959) and at Camp 83 (5900 feet) where similar drilling was accomplished in 1952 and 1953. Dimensional and wiring de- tails of this unit are shown in Figure 3. In the present study it was used for melting a 2 inch bore-hole with power supplied by a portable, 2.5 kilowatt, 120 volt, 1 cylinder, h cycle, Onan generator. The drill unit was suspended by a 7/16 inch manila rope, marked with tape at selected intervals. Conductor wires were G.E. insulated cord (NP-l300)of 0.58 inch (1.5 cm.) O.D., consisting of double copper leads, embedded in composition and sheathed with black rubber. The electrical leads were connected to the drill through a water-tight coupling, as noted in the figure. The drill unit could also be configu- rated with an outside heater coil (No. 12 wire) for drilling in exceptionally cold ice, an arrangement which is diagram- med in the extractor heating element of the figure. This accessory, which requires special care in its use, was not attached in the deeper drill hole at site 8A and, as will be shown, almost resulted in loss of the unit. 8 Vertical alignment of the bore-hole was established at the outset of drilling by means of the inclinometer on a Brunton compass. The general techniques in this type of drilling have been successfully tested and employed in earlier seasons of the Juneau Icefield Research Program. Details have been previously documented by Miller (1952a). Because of the low power and consequent slow penetra- tion rate of the closed-head drill unit in this field work the rate of advance, as logged in Appendix 1, can be used for interpreting sub-surface ice structures and density differences. The thermal borer and generator were operated from 1815 hrs. on 29 August to 1115 hrs. on_h September 1961. This comprised a total of 136.5 hours of nearly continuous drilling. During this period, there were short intervals, totalling 6 hours, during which the generator was not run- ning; and, therefore, when the thermal borer was not pene- trating the firn-pack (for these breaks in the record also refer*to the drill log in Appendix 1). At three different depths during the drilling a knot in the suspension line at a point 20 feet above the borer ap- peared to freeze into the bore-hole (v. position of small triangles in Fig. A). This occurred on two occasions while the generator was running; the first of these at the 29-foot depth and the second at 131 feet. The third freeze-in oc- curred at 120 feet while the generator was stopped for re- pairs. On each occasion extraction of the unit was only 9 possible after pouring anti-freeze into the hole. The rea- sons for this freeze-in were the bulkiness of the knot bringing it in close contact with the wall of the bore-hole. Also, as substantiated by the englacial thermal measurements discussed later, the entire 151-foot section of firn-pack penetrated by the borer was characterized by sub-freezing conditions. Although Miller (1955a) has reported sub-freez- ing conditions.at shallow depth in this high névé the freez- ing of the knot at the cited depths represents the first em— pirical evidence that relict cold exists in the crestal nevé at great depth. This finding is of critical significance to to other interpretations to be dealt with later. By reference to the 1961 thermal drill plot (v. solid line in Figure AA) it is seen that the first 22 feet of the bore-rate curve is hypothetic, having been extrapolated from the measured changes in density given in Figure AC. Thus, electro-thermic drilling commenced in the bottom of a 22-foot section drilled by means of a S.I.P.R.E. 5 inch O.D. hand auger (Fig. 5).1 For purposes of plotting, the refer- ence datum is the top of the hole...i.e. the level of the 1961 late-summer ablation surface. The marked variation in drill rate, as shown in Figure AA, requires explanation. This will be considered after 1. Designed by the Snow, Ice and Permafrost Research Estab- lishment of the U. S. Army Corps of Engineers; a model of which was manufactured for the Juneau Icefield Research Program by the General Mechanical Company of Chicago, Illinois. 10 review of the glaciothermal and sub-surface percolation and stratigraphic measurements obtained at the 8A and 88 sites. 2. 1961 Thermistor Measurements and Englacial Temperature Conditions Glaciothermal measuring equipment was provided by the Foundation for Glacier Research on specifications designed and manufactured for this program by the Geophysics Labora- tory of the U. S. Geological Survey. The applicability and use of this type of equipment for englacial temperature measurements has also previously been described in detail by Miller (1955a). The thermal sensors are thermistors, embod- ied in vulcanized cables (v. Fig. 6). The thermistors are manufactured by the Western Electric Company (type 17A) and consist of "small discs of sintered manganese and nickel oxide, 0.2 inches in diameter and 0.0h inches thick. An axial copper lead, 0.02 inches in diameter, is secured to each with an intermediary spot of ceramic silver paste. The resulting alloyed semi-conductor provides a h.h percent neg- ative change in electrical resistance per degree Centigrade change in temperature at room temperatures and a 6 percent change per degree Centigrade in the vicinity of -30°C. Meas- urements can be made to an accuracy of 0.01°C by means of an appropriate Wheatstone Bridge" (Fig. 6). Fifty to 180-foot cables of spaced thermistors were em- ployed. Two cables, designated as Nos. 332 and 333, were installed in Bore-holes III, IV, and V, at the locations noted in Figure 2. This provides information supplemental to that obtained in Bore-holes I and II during the preceding ten 11 years by Dr. Miller (also v. Fig. 2). Thus, englacial tem- perature measurements were obtained on the crestal névé at Camp 8A (5950 feet) and on the Gilkey Névé at Camp 19A (6500 feet). Each cable was 180 feet in length, embodying l8 thermistors with a 10~foot spacing. Both cables were re- calibrated by the U.S.G.S. Geophysics Laboratory in the spring of 1961 and therefore are considered to have suffered insignificant drift and to be accurate to the limit cited above. Cable No. 333 was placed in the 151-foot bore-hole at Camp 8A (designated as Bore-hole III in Figure 2). Cable No. 332 was placed in a 60-foot hand-auger hole (Bore-hole IV) approximately hO feet west of Bore-hole III. Later this cable was moved to another 60-foot hand-auger hole (Bore- hole V) at Camp 19A. In each case the cables after instal- lation were sealed at the top of their respective bore-holes and left to stabilize for periods of 2h to 72 hours before measurements were commenced. Successive thermal readings were then obtained at all thermistor levels on a 6 to 2b- hourly basis. The dates and hour of installation, and the recorded measurements on each cable are given in Appendices 2-7. The thermal profiles, plotted for stabilized conditions, are shown in Figure hB. An examination of Figure RB reveals the presence of the 1960-61 winter's cold wave in the 8A-8B sector, as well as in the Gilkey firn-pack. This is well demonstrated by the marked decrease in temperature between the surface and the 12 depth of 50 feet, with minimum, -O.9OC, noted at 30 feet. Below 60 feet a relatively constant temperature (-0.05°C) exists. The curve indicates another zone of relict cold at a depth of l20-1h0 feet. It was at this level that the deeper freeze-in of the haul-rope occurred. It appears significant that the temperature profiles obtained from the 60-foot Bore-hole IV at site 8A, and to the equivalent depth in Bore-hole V at site 19A, are almost identical. Additionally there is the fact that these follow the trend of the deeper thermal curve in Bore-hole III. The measured temperature depression in each of the shorter bore- holes, however, is considerably less than in the deep bore- hole. Although this could be the result of lateral temper- ature differences in the firn-pack, it is more likely due to size differences in the bore-hole. The shorter holes were bored with a S.I.P.R.E. auger drill which through frictional erosion produced a 5-inch diameter hole to the depths involv- ed here as opposed to the 2-inch diameter of the thermal bore-hole. Such a larger hole may be expected to create a poorer side-wall contact with the temperature sensors, as well as to permit more air circulation than in the smaller bore-hole. These factors would tend to equalize the record- ed temperatures and minimize the detection of variations. Thus, the data from Bore-hole III are considered as most rep- rese n tative . The fact that, in spite of reduced magnitude, the same trends are indicated in Bore-holes III and IV...i.e. at both 13 the 5900 and 6500-foot elevations -— implies that thermal conditions are similar at least to 60 feet in both of these high nJvés. With this interpretation in mind the curve for the 151-foot bore-hole at 8A may be used as a guide curve to indicate the thermal conditions to be expected in the higher névé at site 19A. Therefore, the 1961 measurements on the crestal and Gilkey Névés, coupled with data from August, 1960, at Camp 8B (v. Fig. hB) corroborate the suggestion that these upper reaches of the Juneau Icefield are sub-Tem- perate (Miller, 1956). This is in contradistinction to the fully Temperate condition which has been previously reported on the lower elevation névés and which.characterizes most of the ice masses on the periphery of the icefield, such as the Lemon Glacier. In Figure AB is also plotted another temperature profile obtained by M. Miller and B. Prather (Personal communication) in late August, 1958, at site 8Y (Fig. 2). This record site lies at 6700 feet elevation on a névé apron a quarter mile north of Camp 8. Here the profile appears isothermal, its temperatures ranging so close to 0°C.1 The slight sub-freezing condition at the 2-foot depth on the 8Y profile may be explained by the fact that the thermistors were implanted during a sub-freezing blizzard. 1. Because of consistently positive readings in this set of data (v. Appendix 7) the plotted zero degree line has been moved 0.0200 to the left. Air circulation in the bore-hole may explain these slightly above-zero readings. This procedure is Justified since a glacier can not be warmer than the limiting value of 0°C. 1A The generally Temperate condition indicated below this level seems anomalous in view of the data at nearby sites 8A and 8B discussed above. When considering the physiography of the location where the readings were taken, however, an ex- planation for the anomaly is suggested. The 8Y site is on the flanks of the bedrock nunatak upon which Camp 8 is sit- uated. Bergschrunds in this vicinity indicate the glacier to be thin (80-150 feet). Thus, geothermal heat emanating from the bedrock could create warming of the ice-cover at this position. Also, crevasses which are found in this sector and which, in some cases, penetrate the glacier, perm mit a great deal of propagated water penetration to depth, as well as air circulation. Each of these aspects would temporize the ice. In addition, the test site is situated on an isolated massif protruding above the main néve surface, and at a position on the northwest flank of the nunatak readily influenced by westerly component maritime winds. Finally, the proximity of this portion of the néve to ex- posed sections of the nunatak enables it to receive a sub- stantial amount of radiant and convective heat from adjoin- ing bedrock outcrops. This also results in a greater prop- aga tion of melt-water, with attendant downward percolation helping to warm the ice. Such sectors of the nevé, there- fore, being thinner and on the flanks of the main glacier, need not exhibit the same geOphysical characteristics as the main body of the ice beneath the névé of the crestal plateau. In summary, a sub-Temperate condition in the upper Taku, 15 Gilkey, and Llewellyn Névés is not surpris ing when consid- eration is given to the substantially colder climate and greater net accumulation that are presently encountered here. This is, of course, relative to the even more temporized climatic character of the lower névé at the level of Camps 10A and 10B, and indeed of the Lemon Glacier in the vicinity of Juneau. C. Ablation and Melt-Water Percolation The magnitude of surface melting and rainfall, and the resulting percolation of propagated water through the firn were also studied on the main icefield. Emphasis was placed on extending previous ablation records with respect to the lower névé, while the effects of water migration were more closely studied on the higher reaches. 1. Main Crestal Névé On the crestal plateau at site 8A a test pit was ex- cavated in the firn to a depth of 20 feet in order to inves- tigate melt-water percolation and to record the firn strat- igraphy. Four melt-water funnels were placed 3 feet into re- cesses in the west wall of the pit at depths of 5 inches, 28 inches, 58 inches, and 88 inches below the 1961 late-summer ablation surface (v. Fig. 10). From each, rubber tubes ex- tended into collection pans in the pit for the periodic measurements of propagated water. The mouth of each funnel used is 12 inches in diameter and is covered by'a‘wire-mesh screen to prevent contamination by loose snow or firn. This equipment has also been described in detail in previous re— 16 ports of the Juneau Icefield Research Program. Each instal- lation was completely covered with firn to insulate against atmospheric influences. Thus, secondary melting due to heat- ing of the metal funnel by air circulation or solar radiation could be eliminated. In Appendix 8, the amount of percolated water captured per day is tabulated. The record, taken from 25 August to 13 September 1961, shows relatively little melt-water generated during the days previous to 8 September. Contemporaneous meteorologic records obtained at Camps 8 and 8A reveal that over this period the temperature hovered around the freezing point; with atmospheric conditions varying from blizzards to CAVU. On and after 8 September, and especially after 10 September, significant increases in melt-water percolation were detected. This is considered related to the first sub- stantial accumulation of autumn...i.e. a 12-inch snowfall on 7 and 8 September succeeded by clear skies and a strong rise of ambient temperature persisting from 10 to 12 September. The combination of moisture-laden snow with subsequent above— freezing temperatures and brilliant sunshine resulted in significant melt-water drainage in the uppermost funnel, positioned 5 inches below the 1961 ablation surface. The second, third, and fourth funnels, however, received little melt-water through this entire period of record. This sug- gests that the increase of surface percolation reached hard- ly deeper than the first funnel.and did not penetrate signifi- icantly to the 28-inch, 58-inch, and 88-inch depths. 17 The above is not surprising in view of the englacial thermal conditions which have been recorded. Since the firn was characterized everywhere by temperatures below 0°C, the melt-water was apparently reclaimed by freezing before it could percolate to any great depth. The existence of vari- ous ice strata and related diagenetic structures bear this out. Details of this process will be discussed in section IID under the heading, Firn Stratigraphy and Structure. Ablation stakes were also set out across the crestal névé. The alignment of these stakes was westward from site 8A to the junction with the Vaughan Lewis Névé (Fig. 2). Subsequent measurements on these stakes revealed a total gross lowering of the n‘vé surface by ablation during the full month of August to be in.the order of 11 inches of firn. Most of this ablation occurred during daylight hours, the effects being negligable at night. A review of project records from previous summers indicates that this statistic is minimal compared to ablation effects on the lower névé. The 1961 statistics from Camp 108 further bear this out, as discussed below. Precise diurnal records were not obtained because of the periodic snowfalls on the upper névé, the effects of which nearly'balanced out the surface reduction by ablation (v. Appendix 9). 2. Main Lower Névé On the lower névé in the Camp 103 area (3650 feet) a 1.3 mile traverse line was set out, along which 9 ablation stakes were positioned 300 yards apart. This traverse l8 originated at the base of the Camp 10 nunatak and extended in a west-southwest direction (Figs. 2 and 8). The result- ing gross ablation record for each point is plotted in Fig- ure 7 for the period 25 July through 26 August 1961. The daily records for each stake are referencedin Appendix 10. Total ablation for this interval averaged A8 inches of firn with respect to the broad central segment of the névé. This is more than A times the ablation for a comparable period in August on the crestal névé. Up to 72 inches of firn surface lowering was recorded over the same interval in the ablation moat adjacent to the Camp 10 nunatak. In the Camp 8 sector, 2500 feet higher in elevation, no ablation moat occurs, probably due to a much smaller area of exposed bedrock as well as to the factor of much less ablation. In contrast the névé area adjacent to the extensive exposures of bedrock on the Camp 10 nunatak is subjected to air con- vection currents and radiation from the rock. This provides adequate explanation for the greater amount of ablation ob- served in the marginal zones. Throughout the lower névé, especially below 5000 feet, moat features are visible wher- ever nunataks protrude through the icefield. The broad central parts of the lower névé experienced less ablation not only because of their distance from rock outcrops but also due to their subjection to diurnal move- ments of cold katabatic air draining from the crestal sector. Figure 8 shows the ablation per day measured at each of the stakes during the period of record. The curves are 19 similar in eacticase, differing mainly in magnitude. This cor- respondence of peaks and troughs in spite of the erratic na- ture of the individual curves, suggests regional significance. By examining Figure 9 we have quantitative proof of the rela- tionship to key meteorologic parameters. In this figure a plot is shown of the mean ablation of all the stakes for each day of record.1 It can be seen that the ablation curve fol- lows, fairly closely, the temperature curve; and, to much.1ess extent, parallels the histograms of precipitation. Such a condition is due to the minimal melting effect of rainfall in the névé zones of'tte Juneau Icefield because of the less- ttnn-AOoF temperature condition of liquid precipitation in these areas. This corroborates the conclusion of previous investigators on the Juneau Icefield Research Program and of Wallén (19A8) in his studies of climatologically comparable Scandinavian glaciers that the main control of ablation in the regions studied is ambient air temperature, even during periods of rainfall. Specific melt-water studies on the lower névé were not conducted during this field season, however reference is made to the measurements of Leighton (1952) who, during the summer of 19A9, found that melt-water was readily generated during all hours of the day, and to a lesser degree, throughout the night. He too observed direct correlation l. The dashed area of the ablation curve represents averages over the days involved, since daily synoptic measurements at Camp 10 were not obtained during these intervals. 20 between daytime melt-water production and diurnal rise and fall of anbient temperatures. Also, with similar melt-water recording equipment he noted increased concentrations of melt-water in the firn-pack withciepth. This is in contrast with the crestal névé where it is clear that far less halt-water is generated, and this only during the warmesti hours of daylight. Also, in the Camp 8A firn-pack, no concentration with depth was observed during the period of August-September. In this regard the differ- ence between the creatal and lower névés may be explained by the glaciothermal conditions discussed in section B2 of this chapter. A good share of the melt-water in the Temperate névé at lower elevations passes into the glacier at depth (Miller, 1962). This drains toward the terminus through englacial.and subglacial channels, eventually emptying into Taku Fiord. In contrast, the englacial thermal.conditions in the sub-Temperate névé of the crestal zone blocks the drainage of most water generated at the surface by reclaim- ing it through freeze—immobilization in the sub-freezing firn and firn-ice, and possibly even in bubbly glacier ice which, according to the reduction in thermal drill rats (Fig. AA), might prevail below about 110 feet. In the Camp 9 area ablation measurements were taken from 8 stakes pn an east-west traverse across the intermedi- ate (A600-foot) névé. A total lowering of approximately 10 inches of firn over a lO-day period was measured in August, 1961. The dataare recorded for future reference in Appendix 11. 21 3. Mode of Percolation The percolation of melt-water through the firn is not entirely vertical, nor is it uniform. As noted above, per- colation water can become concentrated with depth under con- ditions where melt-water is generated in copious quantities and where conditions are sufficiently Temperate to allow it to coexist in a firn-pack or in ice without freezing. This concentration at depth may be attributed to the increase in density and consequent decrease in permeability in deeper firn. Also, planar and cross-cutting ice structures which so readily form in Temperate glaciers (Leighton, 1952) affect the concentration of mobile water. These features, once they develop, divert the normal vertical flow that would occur in homogeneous firn, and cause it to move downward in all di- rections...i.e. varying from horizontal components to diag- onal and vertical. Therefore, the impression that a uni- formly descending melt-water front exists in the firn of a Temperate glacier is in many cases erroneous. Instead, lo- calized concentrations of melt-water occur in irregular zones where percolation is either guided or impeded by re- strictive ice structures. Such selectivity in paths of flow, when coupled with repeated refreezing of melt-water in the firn, tends to accentuate diagenetic ice structures al- ready formed (Miller, 1962a). This fact can explain the presence of unusually thick ice strata and related ice glands, particularly at the deeper levels. In the 1961 season such were observed dramatically exposed on crevasse walls at the 5700-5800-foot level in the Camp 8 sector, and 22 especially at site 8A as noted below. Lesser ones were also found in a test pit on the 5200-foot névé at Camp 9. D. Firn Stratigraphy and Structure Firn stratigraphy deals with the annual accumulation or yearly firn increments found in a firn-pack. In each such segment freshly fallen snow of a density 0.1 has suffered destructive alteration followed by constructive crystal met- amorphism before it has changed into firn at a density of 0.50-0.75. With increasing depth these segments grade into firn ice (0.75-0.88), and at the deepest levels into bubbly glacier ice (0.88-0.90). The agents of this metamorphism are primarily compaction and regelation with melt-water percolation having a supporting affect. Incorporated within the firn-pack on this icefield, an extenSive development of varied.ice structures has been pre- viously reported in publications of this long-range program. These have been described as various thicknesses of ice strata, and various forms of lenses, pods, columns, dikes, etc. But regardless of morphologic differences they are all the result of surface water percolation and refreezing of liquid water at depth. On the lower nevés where Temperate conditions prevail they can only serve as an indicator of the magnitude and extent of melt-water generation during the spring amelioration period. On the highest nJv‘s, however, they represent development during the whole of the ablation season. Hence, an extrapolation of tin volume of these secondary ice structures at the 8A-BB sites will be attempted. 23 1. Main Crestal Névé Firn-Pack The data on accumulation and stratigraphy serve as a continuation of and supplement to records at sites 8A, 8B and 8x in 1951, 1952, 1953. 1958, and 1960.1 The 1961 re- cords were obtained in bore-holes and from the walls of test pits and crevasses. Tabulations of these measurements, in- cluding those from the Gilkey Névé, are given in Appendices 12, 13 and 16. By reference to this set of statistics de- lineation of the annual sequence of firn accretion is at- tempted for the period 1951-61. a. Primary Stratification: Some of the data in 1961 were obtained through gross examination of the S.I.P.R.E. auger cores from the 60-foot bore-holes at 8A and 19A. The resulting information is plotted in Figure 11, with provi- sional correlations suggested by dashed lines. Additional information may be derived from the 151-foot bore-hole at 8A by interpretation of the 1961 drill-rate curve given in Fig- ure AA. The measurements obtained from test pit and cre- vasse walls were at sites noted in Figure 2. Of particular importazlce are the crevasse data from the 5700-foot level 2 miles south of Camp 8. These records are presented in Fig- ure 12. Correlation of the data obtained from the same sites in the 1958 and 1960 summer seasons (Miller, Personal com- munication) has given credence to the time sequence depicted in this figure. l. The 1951-53 records can be found in J.I.R.P. file re- ports, Foundation for Glacier Research. 2A Figure 10 depicts the wall structure in the test pit at Camp 8A. This represents a detailed picture of the strati- graphy and structure in the annual firn-pack, as of 9 Sept- ember 1961.‘ On this date the stratigraphic thickness of the 9. 1960-61 accumulation stratum was 17.5 feet; with a density range of 0.52 to 0.59. This is in considerable contrast to the 7 feet of retained 1960-61 firn-pack (v. next section) .measured at site 10B on 1A September 1961.' Each of these dates may be considered as close to the end of the 1960-61 budget year. The excessive difference in thickness between these accumulation segments further substantiates the exist- ence, under present climatic conditions, of a zene of maxi- mum net accumulation on the higher reaches of the Juneau Ice- field (Miller, 1956). This is both a factor of greater snow- fall received on the crestal néve (in spite of the fact that higher mountains exist farther east) and greater ablation affecting the lower ne’ve’ on the maritime side of the cordil- lera. In other words, elevation, geographic poSition, and orographic influences are together the prime factors con- trolling the magnitude of retained accumulation. b. Density Determination: Density profiles of the firn in the Camp 8 sector are plotted.in Figure AC. The data were obtained in early September using a 500 cc. hand corer Lin the 8A test pit, and the S.I.P.R.E. auger corer in Bore- hole IV. The bore-hole densities were determined at irregu- lar intervals to a depth of 58 feet below the 1961 ablation surface (v. Appendix 17). The test pit curve represents the 25’ record at 12-inch intervals through the 1960-61 firn-pack (v. Appendix 18). The bore-hole cores represent single samples. All density values in the test pit sequence represent aver- ages of two or more readings. This is one or the reasons why the bore-hole curve varies over a greater range of densities than the pit wall curve. Another is the occasional presence of ice strata or laminae1 in the bore-hole samples, as op- posed to the test-pit cores where more caution could be used in the sampling of uncontaminated firn. Mention is made of the greater bulk density indicated at site 19A, compared to 8A, as suggested by the stratigraphy in Figure 11. Later discussion of this anomalous indication wiLL be made. Density measurements were also obtained in an 11- foot test pit (elev. 5200 feet) at Camp 9. Although these data are not plotted, they are referenced in Appendix 19. Generally, the densities at the Camp 9 site were higher than at Camp 8A. As for the lower névé, a bulk density value has been es- timated from comparable late-summer surface firn thicknesses measured over the past decade by earlier expeditions of this program. Each profile is, in detail, irregular, but as ex- pected exhibits a relatively linear trend of increasing den- sity with depth. By projecting the average line of linear in- crease over a profile, a bulk density value is derived. The bulk density value in the crestal névé sector (site 8A) for h 1. Defining an ice stratum as relatively thick...1.e. great- er than 3 mm. - and an ice lamina as thin...i.e. less than 3 M0 26 the 1960-61 firn-pantis 0.56. This is generally lower than that found at Camp 9, and much lower than that for the 10A- 10B sector as recorded at the end of the ablation season in earlier years (J.I.R.P. reports). The upper névé bulk den- sity of 0.56 compares closely, however, with the 0.55 bulk density of the 1951-52 firn segment recorded in the surface firn at the same site 10 years ago (Miller, 1956, Fig. A0). These relatively lower values and their general similarity may manifest the consistently more Polar glaciothermal char- acter indicated in the higher firn over the past decade. This inter-relationship is reasonable since colder englacial conditions would tend to minimimecompaction and also restrict the development of capillary water; factors which substan- tially affect density increases in surface firn. c. Secondary Englacial Structures: In conjunction with the foregoing measurements, the nature and extent of diagen- etic ice structures in the crestal firn were also investigated. A diversity of ice structures was observed including strata, laminae, lenses, columnar masses and annual "dirty" layers. In the test pit at Camp 8A only the 1960-61 firn-pack was observed. No "dirty" layers were present but extensive diagenetic structures were found. These are illustrated in cross-section in Figure 10. Keeping in mind that this cross- section involves only young firn, relatively thick ice strata are a surprisingly dominant structure. Many of the thinner, less extensive strata thinned out to lamina size. This group of structures ranged in thickness from 0.2 inches (intermit- tent) to A inches. The thickest strata were continous and 27 extensive. In the 8A sector only a very few ice columns were ob- served. The largest measured 2 feet in height and 3 inches in diameter. 0n the névé plateau at site 19A, however, a very extensive array of ice columns, 2 inches to 10 inches in diameter, were found pimpling the nevé surface in late August. This was just before the first winter snows ob- scured this feature. The greater abundance of these features on the Gilkey Ndve, compared to the crestal ndvé, may ally to the greater bulk density value suggested.at the 19A site. These facts suggest a slightly more maritime condition for this highest névé, further corroborated by an increased salt content as discussed in section IIE. The probable reason for this anomalous condition points toward m1 orographic control which allows maritime winds to sweep unimpeded into this par- ticular sector via the Berners Bay Trench. For the 5900-foot level, the relative proportion of ice structures to the volume of firn is estimated from the wall profile in Figure 10. The figure derived is about A percent, which is comparable to the proportion of diagenetic ice in 1960-61 firn exposed on the crevasse walls at the 5700-foot site. On these same crevasse walls the volume percentage for the 1959-60 and 1958-59 firn segments appeared to be 6 per- cent or more of discrete diagenetic ice. The structures in- volved were also primarily ice strata. A number of associ- ated "dirty" layers, however, connoted annual ablation sur- faces (Fig. 12). The term "dirty" layer is used to denote a layer of mixed dirt and firn, the dirt being primarily com- 28 posed of dust and including organic particulate matter blown onto the ndvé by wind. Concentration of this material at the surface occurs by the end of summer through ablation. Spe- cial consideration of these as annual accumulation strata in- dicators has been made by Miller (1955b). 2. Main Lower Névé Firn-Pack The 1961 firn-pack accumulation statistics for both the intermediate and main lower nevés are tabulated in Appendices 1A and 15. a. Primary Stratification: On 1A September, a date close to the end of the annual ablation season, examination of crevasse walls in the vicinity of ablation stake E on the traverse (v. Fig. 8) showed approximately 7 feet of the 1960- 61 retained accumulation. From the record plotted in Figure 9, it is seen that in this sector an average of 1.5 inches of firn ablation per day occurred during the late July-August period. This is borne out by an earlier observation on 25 July of approximately 13 feet of firn for the segment of 1960-61 retained accumulation. Assuming comparable ablation from.May to mid-July of l96l...i.e. a minimum of 5 feet of old snow (roughly equivalent to A feet of firn)-— the total solid precipitation for 1960-61 on the lower névé is in ex- cess of 17 feet of firn. Using a bulk density of 0.60, which approximates late-summer firn density, the 7 feet of firn yet retained on lA September is equated to A.2 feet of positive accumulation, water equivalent. By using the 1.5 inch per day gross ablation figure, and extrapolating to the end of the 29 ablation season (to approximately 25 September as discussed in section IIG) the net accumulation on the lower nevé for the 1960-61 budget year is calculated to be 3.A feet water equivalent. Since 17.5 feet of firn remained on the crestal plateau -which at a bulk density of 0.56, approximates 9.8 feet wann' equivalent-—-it might at first be considered that the gross accumulation at the higher level was greater. Another explan- ation of this relative difference, however, is the retention of frozen surface water in the crestal firn-pack as well as reduced ablation on this névé. In other words, the consid- erable difference in observed firn-thickness may largely be due to excessive ablation and runoff on the lower ndvd. b. Secondary Englacial Structures: The diagenetic structures in the firn of the lower nevé, described by Leighton (1952) and Miller (1952b) during the l9A9 field season are of similar morphology to those in the firn of the crestal plateau. The lower elevation structures, however, appear in greater profusion than do the crestal counterparts. This is expected since the combined rainfall/melt-water ef- fects are maximum in spring and autumn when the lower ndvd is changing to or from a completely isothermal condition. A few statistics are cited to bear out this conclusion. In the 19A9 firn-pack, Leighton calculated that ice strata constituted 8 percent of a test pit wall in the Camp 108 sector. In 1950, 1951, and 1952 Miller (1962a) determined respective propor- tions of 10 percent, 10 percent and 7 percent in the 10B 30 surface firn-pack of each designated year. Correspondingly ttn proportion in the 8A-8B firn-pack in 1951 was 5 percent by volume; and in 1952 again 5 percent. This compares with a h percent proportion of ice strata in the 1961 firn-pack attflh In addition, it is to be remembered that all liquid water generated on the sub-Temperate crestal nave is reclaimed by freezing, so that some diagenesis must occur at all times during the ablation season. This is distinct from the lower neve where most of the ice structures contained in the firn form mainly in the early part of the melting season while the winter cold wave is still present. Propagated surface water percolates downward releasing its latent heat to the colder firn in the process of freezing into the various ice struc- tures. After the winter cold wave is dissipated (on the névé usually prior to July 1st) the propagated water no longer freezes but percolates to greater depths and eventually pas- ses into subglacial drainage channels where it drains off. Hence, a great deal of liquid water is lost from the lower neve while most, if not all, is recovered on the crestal plateau. Further information on this phenomenon may be pro- vided by the glacio-chemical investigation cited.below. E. Glacio-Chemical Analysis To provide supplemental information on the provenance of precipitation on the icefield various samples of firn and ice have been taken in the summers of 1950, 1960, 1961 and in the winter of 1951.1 These samples have each been subjected to 1. See Miller, M.M. (1953) for listing of saline records, 1950 and 1951. The 1960 and 1961 records are referenced inAppendix 33. 31 chemical determination of their NaCl content.1 Decontami- nated plastic bottles were used to hold the samples, and great care was taken to collect samples in the natural state. 1. Significant Icefield Variations a. Areal Distribution of Salinas: Figure 13 contains a plot of the NaCl content on the late-summer nave surface from the 3500 to 6500-foot levels (i.e. Camps 10B to 19A). The data are not yet sufficiently extensive for firm conclusions, but they reveal some general facts suggesting provisional in- terpretations. It is noted that the data are not from one year but from several years, and that all but one set of data were obtained at the end of summer; the exception being the record in mid-winter. In the figure it is apparent that winter surface salini- ty is distinctly lower than that observed under summer con- ditions. This is expected, since summer ablation and result- ant percolation tend to concentrate the salines. Perhaps more importantly, a winterato-summer increase in salinity may represent an increase in wind-blown oceanic vapors over the icefield during the highly humid summer months; with colder, drier, and relatively salt-free continental air being the rule in winter. It is of significance that the NaCl-rich 5100-foot and 6500-foot samples indicated on the plot were 1. Procedure used for these analyses is the official method as described in "Standard Methods for the Examination of Water and Sewage" published by the American Public Health Association, 1936. The determinations for these icefield samples were made by H. Kothe. 32 collected Just after southerly (maritime)storm winds passed over the icefield. Although the data are insufficient, they point the way to future fruitful measurement of this type. Another potential climate indicator may be the testing of firn for salines carried to the icefield by terrestrial winds, as opposed to those of marine origin.1 The p.p.m. content may be extremely low, as compared to that of salines brought in by wind-blown oceanic vapors. Areal relationships over the icefield of contrasting terrestrial and marine-de- rived salines may prove to be significant in glacio-climato— logic studies. Much work is needed, however, to prove the validity of this concept. Traverses over the icefield should be made both at the beginning and end of the field season to obtain saline sam- ples for the glacio-chemical studies; and this should be done over a period of consecutive years. An assembly of such data should make possible further interpretation of storm track patterns and possibly reveal in detail cyclic shifts in mari- time vs. continental air mass effects on this icefield from season to season and year to year. b. Depth Distributicn of Salines ard Interpretatim of Anomalies: Figure 1h plotted on a semi-log scale, shows the variation of saline content with depth in the firn and underlying ice of the lower neve in 1950 and 1951 at Camp 10B. Figure 15 com- 1. It should be noted that salines carried by terrestrial winds are of an entirely different chemical composition than those of marine transport. 33 pares the saline variations in the crestal nave firn-pack as recorded in 1961 at Camps 8A and 19A. In each of these fig- ures the data are similar and show insignificant variation in chloride content at shallow depths. Even in the Camp 10B area, the 1951 data reveal no detectable change between mid-winter and summer. This suggests the dominance of maritime storms in this sector regardless of season, and the probability that saline dispersion at depth, as a result of water percolation, had not yet begun by 11 June in this particular year. The corollary of this is that the winter cold wave was still in- tact at the sample level, a fact borne out by thermal observa- tions in that same year. The deeper analyses from Camp 108 as shown in Figure 1h were obtained from rotary drill cores. There is much more variation and a greater proportion of salines in these samples 13mm of their shallower counterparts. Although this may in part be the result of secondary concentration through blockage of percolation water by diagenetic ice, one is tempted alter- natively to invoke the mechanism of cyclic storm-track shifts to provide an explanation. This consideration is discussed more fully in the following section on climatologic impli- cations. At least one anomaly in the foregoing statistics may be explained by orographic controls. This is the previously cited record from site 19A on the high-level Gilkey Nevd. As shown in Figures 13 and 15 we find a suggestively higher sa— line content from that in the shallow depth samples at site 8A. One must bear in mind, however, that site 19A is 311 situated in the nourishment zone of the Gilkey Glacier at the head of the Berners Bay Trench. Here maritime winds are chan- neled directly up from the coast unimpeded by any barrier of mountains or bordering ridges. Hence, an increase in salinity should be expected in this particular locale, compared to the more continental positions found on the crestal plateau to the south and east. Concurrently, a reduced salinity should be expected in samples in the vicinity of Camp 20 and in the neve of the Llewellyn Glacier to the east (Fig. 1). Also an anomalously high value of 7.h p.p.m. was deter- mined from a surface sample at Camp 108 in August, 1951. The meteorologic records1 show a prevelance of maritime westerly and north-westerly winds over the 3-week period preceding the sampling date, which may account for this relatively high value. An alternative or supplemental explanation may lie in the excessive ablation occurring during that season, which resulted in the highest nave-line2 of the past 20 years. At the 10B site this would mean superposition of the 1950 and 1951 ablation surfaces (multiple ablation surface) with ex- cessive concentration of salines. In general whatever interpretations are made with re- spect to saline concentrations the available data are too limited to allow definite conclusions. They do, however, provide some corroboration of other interpretations in this l. Juneau Icefield Research Project, Report No. 8, 1951 field season. 2. Receded up-glacier to a position well above Camp 10B...i.e. to 3800 feet. 35 study; and they indicate a useful direction for future meas- urement. For example they may provide a further means of analysing the selective modes and extent of melt-water per— colation. Another possibility, indicated by the above,is the identification of saline concentrations on ablation surfaces or multiple ablation surfaces. This could be a most useful criteria for identifying such horizons on ere- vasse walls, in test pits or in bore-hole core samples in sub-Temperate to Polar firn where the effects of melt-water diffusion are minimal. 2. Climatologic Implications ' The Juneau Icefield is located, meteorologically speak- ing, in the coastal interaction zone between a dominantly maritime climate toward the southwest and a dominantly con- tinental climate to the northeast. Being geographically so positioned, the icefield is subjected to both climates de- pending upon what fluctuations or controls cause one or the other to dominate. According to the Solar Control hypoth- esis (Miller, 1956, 1958), reduced solar radiation of the corpuscular type will cause the maritime climate to be dom- inant while a high corpuscular radiation causes the contin- ental climate to move south-westerly and force'the maritime climate seaward. Also, in the winter season, the continen- tal climate appears to dominate in the crestal plateau area subjecting it to northerly and north-easterly prevailing winds. It can be postulated what effects sush.fluctuations would have on saline percentages in the neves over the ice- 36 field. The maritime climate when dominant, may be expected to bring in the NaCl—rich vapors with associated rain and; snowfall from the ocean; while a lack of chlorides would char- acterize rain and snowfall over periods of continental domi- nance. But the problem remains whether or not the salt con- centrations over the icefield and their variations in each ac- cumulation year are sufficiently distinctive to indicate con- clusively such climatic shifts during any particular period. c It is of interest, therefore, that in terms of present depth and measured creep rate of the glacier between the up— per and lower nevés, material from which the deep core samfims were taken (Fig. 1h) accumulated in the general vicinity of Camp 8 approximately h5 years ago. At that time the radia- tion cycle was at its minimum position...i.e. low sunspot num- ber. According to the corpuscular mechanism the climate in this region u5 years ago would have been more dominantly low pressure and maritime, therefore, subjecting the crestal nevé to oceanic, saline-laden winds. At the present time, with sunspot activity close to an 80-90 year peak, a theoretically high pressure, drier, and more continental climate should pre- vail, particularly over the upper reaches of the icefield. The theoretical consequence would be a displacement of mari- time air masses coastward, so that they would influence pri- marily the lower and peripheral neves. Thus, in this decade the crestal ndvé should be receiving less salines than the lower nevé, or for that matter the Lemon Nave, and relatively far less than a half solar cycle ago...i.e. h0-h5 years. Such a relationship is tantalizingly suggested by the higher 37 proportion of salines at depth as illustrated by the data in Figure 1h. In order to obtain any conclusive results of the fore- going type broader and longer-term analyses are needed, with a far more extensive collection of samples obtained in each year. For example comparative samples should also be collectmi from the Lemon Neva. In this way sufficient data can be ac- cumulated to determine the use of saline analyses as a crite- rion for the reconstruction of accumulation and storm-track trends, and for tho further understanding of related glacio- thermal variations. To explore another set of corroborative data, we now turn to the analysis of data in Appendix 1,...i.e. the drill log of the electro-thermal bore rig used for deep penetration of the crestal firn. F. Interpretations of the Crestal Neve Thermal Bore-Hole Data Reference is once again made to Figure uA. The high pen- etration velocity indicated in the first few feet of thermal drilling is undoubtedly the result of low density in the young surface firn. The much reduced drilling rate from 5 to 39 feet, at first thought might suggest a logical increase in density with depth. This slowing down, however, is attributed at least partially to another cause. Englacial temperature measurements, made upon completion of the bore-hole, show con- sistently sub-freezing conditions.1 Negative temperatures (-0.13 to -0.89°C) were encountered from 5 to 50 feet in the 1. As discussed in section IIB2. 38 firn and are believed to represent the previous winter's cold wave (Fig. hB). This encompasses the very depths at which the reduced drill-rate occurred. The increased bore-rate between M1 and 65 feet suggests attenuation of the relict cold zone; with the firn down to the 151-foot level being slightly sub-freezing, at a relatively constant temperature of -o.05 to -o.1o°c. While drilling in a "colder" zone, it is to be expected that a thermal borer will be less effective anditherefore slower than when operating in "warmer".firn. ~According to Miller (1952a), the impediment in drilling through a relict cold zone is not believed to be by virtue of significant losses of heat in warming the firn to its melting point (shun only 0.5 calories wouldbe required to raise the temperature of one gram of ice 1°C). Instead, the colder firn surrounding the borer creates a freezing condition along the unheated up- per portion of the bore shaft causing masses of loose, par- tially melted firn and snow to stick to the shaft and thereby increase its frictional drag. The much more gradual decrease in bore-rate from 67 feet downward can be attributed to the normal density increase in the firn and at greater depths to the gradual transition to firn-ice. By projecting an average line of increase through the density curve (Fig. uC) the bulk density at approximately 100 feet is indicated as 0.80 grams/cc. Sudden large decreases in bore-rate (e.g. at the 36, 38, and 50-foot levels) are attributed to substantial ice strata ...i.e. 3 inches or more thick. Most of these are probably 39 associated with annual ablation surfaces. Conversely, note- worthy temporary increases in bore-rate would seem to indicate "depth-hoar" strata. It would be safe to assume, however, that below the lOO-foot level no depth-hoar could be detected by this method since the effects of aging and extensive com— paction would destroy the softness of such zones. The 151-foot bore—hole at site 8A may not have completely penetrated the firn-pack of the crestal nev‘ since a deeper, l7l-foot bore-hole in 1952 at site 8B was provisionally in- dicated as bottoming in firn-ice (Miller, 1952a). Such in- terpretation is supported in the present case by a fair con- stancy of drill-rate below the lO9-foot level at a density, extrapolated from the Figure hC curve, not greatly in excess of 0.80. As previously suggested in section IIC2, however, this reduction in bore-rate may connote bubbly glacier ice. In such event the firn-pack could be interpreted to be roughly 110 feet thick at site 8A. Actual core samples obtained at this depth in a subsequent season would clarify this point. Superimposed on the 1961 bore-rate curve of Figure hA is the 1952 drill-rate curve at the 8A site. This is a smoothed curve based on the detailed plotting of Miller a952a). Al- though the 1952 bore-hole (3.0 inch diameter) was produced by a faster borer (2.0 KW), the drill-rate curve coincides fairly well. In fact it exhibits detail quite similar to the 1961 characteristics below the ho-foot level. This comparison, spanning the last 10 years, implies a consistency in climato- logic and meteorologic conditions over the past decade. Such relationships are significant to the long-term analyses of the no Juneau Icefield Research Program, but they are somewhat be- yond the scope of the present report. Details of the glacio- meterology of the summer, however, are reviewed below. G. Glacio-Climatology To provide basic meteorologic data for the present study and to extend the long-range climatologic record of the program, meteorologic stations were set up at the various research camps on the lower, intermediate and higher neves. At each site temperature, dew point, humidity, precipitation, wind, sky condition, radiation (Camp 10), and duration of sunshine (Camp 8) records were obtained on a 3-hour1y to daily basis. Such data are essential to the climatologic interpretations in the main icefield sector. Comparative records from the Camp 10 nunatak station and from Mt. Juneaul (elev. 3576 feet) are available for extrapolating the Lemon Neva meteorology since these three locations are geographically adjacent and lie at approximately the same elevation. 1. Temperature and Precipitation Measurements 0n the crestal nevé continous records were maintained during the period of field work at the glaciologic station at Camp 8 (6800 feet). Semi-continuous records were maintained ‘at site 8A (5950 feet). These data are listed in Appendices 21 and 22. As may be expected, temperatures at the higher station (8) are consistently lower than those at the lower site (8A). A mid-summer lapse rate of 3.7°F between these two sites 1. A field station on a ridge 1.2 miles northeast of the city of Juneau. kl pertains. This closely agrees with the mean lapse rate of 3.5°F per 1000 feet usually cited for wet adiabatic conditions. Precipitation was dominantly rain from late July through mid-August, with sporadic snow sometimes falling at Camp 8. From late August on, snow was the dominant form of precipi- tation in the Camp 8 sector; with rain persisting till mid- September at Camp 9 (5200 feet) and Camp 10 (#000 feet). In the 1960-61 crestal firn-pack, the ablation season ended on 25 August 1961. On the lower nave, as extrapolated from the Juneau temperature records, the ablation season ter- minated a month later...i.e. about 25 September. The data from Camp 9, situated above and on the eastern edge of the intermediate nave (mean elev. A600 feet), are minimal since the camp was occupied for only two continuous weeks in the 1961 summer field season. These data are given in Appendix 23. Over the period of record in August the dafly' mean temperatures are distinctly higher than on the crestal neve. On this nave sub-freezing autumn conditions developed in mid-September as opposed to the last week of August on the crestal nave. In August all precipitation at Camp 9 was rat» with persistant snowfall observed in the second week of September. 0n the lower nave meteorologic records were maintained at Camps 10 (hOOO feet) and 10B (3650 feet). In Figure 9 the mean daily and minimum daily temperatures for the period 25 July - 27 August at Camp 10 are plotted using data referenced in Appendix 2h. Comparison is also made with the minimum h2 daily temperatures at Camp 10B.1 The minimum temperatures at the latter site vary from 2° to 20°F lower than at Camp 10. As indicated these remained close to but consistently above freezing throughout the period of record (7 July - 1h Sept- ember 1961). It was also noted that the ablation season had not yet ended on the glacier surface at 10B as of the date of evacuation, 1h September. By reference to the full seasonal march of temperatures plotted in Figure 16 the terminal date for the ablation season on the lower neve is indicated as 25 September. This is interpreted from the curves for the sea- level stations at Annex Creek and Juneau Airport, using the standard lapse rate adjustment for the hOOO-foot level. It is mentioned again that the terminal date for the ablation sea- son recorded at the crestal nevé camps was a month earlier. By further reference to the Juneau and Annex Creek curves in- itiation of the ablation season is interpreted as 25 April at the hOOO-foot level. Thus a Semcnth ablation season is in- dicated for the lower névé. 0n the same lapse rate basis an ablation season of 2.7 months is suggested for the crestal ndve...i.e. 5 June through 25 August, Each of these values correspond roughly with ratios observed over the past 16 years. Also as shown in Figure 9 for the lower neve, summer pre- cipitation was almost entirely in the form of rain. For the period of record, the amount of precipitauon at Camp 9 and 10 appear similar; however, longer periods of record are 1. Ambient temperatures measured by alcohol thermometer at a position h feet above the nave surface. M3 needed to evaluate this. 2. Duration of Sunshine Records At Camp 8, duration of sunshine records were kept from 15 August to 13 September 1961. These data were obtained by means of a Campbell Stokes recorder, and are tabulated in Appendix 25 for future reference. The total hours of sunshkm recorded is considered a minimum value, since the instrument could not begin recording at the actual time of sunrise. Thus was due to obstruction by the summit of Mt. Moore, east of Camp 8, which blocked out the sun for the first hour of day- light. No such obstruction existed in the west. 0n clear days, therefore, a one-hour correction factor must be applied in any analysis of these records. In general, as has been shown in previous seasons of the icefield program, duration of sunshine can be directly interpreted with respect to solar radiation measurements obtained at a nearby master station. 3. Solar Radiation Continuous radiation records were obtained at Camp 10 over the period 21 July-114. September. The instrument used was a Belfort Recording Pyrheliometer. The readings, in Langleys (gram.calories per cm2 per hour), are also listed for possible future reference in Appendix 26. These data exhibit close diurnal correlation with sky (cloud) conditions, as would be expected. As with the sunshine data, detailed analysis of the radiation records lies outside of the scope of this present treatment. h. Lemon Glacier Meteorology During the summer field season, the concentration of uh efforts on the main icefield névés precluded occupation of the program's field station on the Lemon Glacier. Therefore, the general meteorologic condition of the Lemon Nevé in the 1961 budget year is interpreted from data obtained on the com- parable elevation néve of the adjoining Taku Glacier system. Additionally useful in the extrapolation of conditions are the Juneau Airport radiosonde records from l9h9 through lgihl Also pertinent are the precipitation records from the compara- ble elevation site on Mt. Juneau, these being obtained by U. S.'Weather Bureau personnel over the summer months of 1961.2 In view of the proximity of these locations and their simi- larity in elevation fair agreement may be expected. It has been shown by Miller (1956) that a high correlation coefficnxm (0.88 - 0.9M) exists between these upper air data and corre- sponding data obtained at icefield nunatak stations. For ex- ample, by reference to Figure 17, the Camp 10 and Juneau Air- port radiosonde mean monthly temperatures may be seen to wane quite closely for the months plotted. On this basis lapse- rate evaluations of the Juneau Airport records have been ap- plied with some degree of confidence in the present analyses. Caution, however must be used when extrapolating these data to the actual nevé surface. As an illustration,the 1961 Aug- ust minimum record for Camp 10B (3650 feet) averages 10°F colder than that at camp 10 (hooo feet). This undoubtedly 1. Upper air temperature data not recorded after 1953. 2. The Mt. Juneau site is geographically proximal to the Lemon Glacier, as shown by its position just northeast of Juneau in Figure 1. AS reflects the katabatic chilling of the broad névé below and west of Camp 10, since this order of mean monthly temperature difference has been cited between these two sites in previous summers (JIRP reports). The temperatures on the comparable elevation Lemon Gla- cier Neva have roughly corresponded to those on the Camp 10B nave although a little warmer, presumably through lack of a significant katabatic effect and by virtue of the closer geo— graphic position to the coast. On this basis the ablation season on the Lemon Nevé is inferred to be of slightly long- er duration than on the lower Taku Névé...i.e. essentially from April into October. With respect to precipitation during the 5-week period of 21 July through 26 August 1961, Camp 10 (h000 feet) re- ceived 1h.5 inches of rain (v. Appendix 2h). The Mt. Juneau site, at an elevation of 3576 feet, during the same period, experienced almost 3 times as much, or h0.6 inches of rain (v. Appendix 27). Review of the shorter term records at Camp 8 reveals that only half as much rainfall occurred at Camp 8 as at Camp 10. Therefore, recognizing that the Lemon Nova and the Mt. Juneau site are in the same generalelocale and at comparable elevations, it may be concluded that the Lemon Neva receives nearly 3 times as much rainfall as the main lower nevé of the icefield 20 miles inland and approx- imately 6 times as much rainfall as the main crestal névé. The exact amounzreceived by the névé of the Lemon Glacier is probably very close to that measured on.Ht. Juneau. These h6 statistics, therefore, well illustrate the extreme maritimity of the Lemon Glacier sector. Concurrently they help to dem- onstrate the relative sub-continental climatic condition“ which pertains on the higher névés of the main icefield. The reason behind the far greater liquid water precipi- tation in the Lemon Glacier area is orographic as well as geographic. Cyclonic summer winds sweep moisture-laden clouds inland from the Gulf of Alaska. Upon meeting the mountain barrier of the Boundary Range they drop their contained moisture as precipitation. As these air masses pass farther inland over the main icefield area the already partially drained air masses have less and less moisture to release, until finally on the lee side of the range the climatologic conditions become semi-arid. This relationship is well mani- fested by the sub-Temperate englacial condition of the crestal neve; by the relatively higher nave-line on the Llewellyn Glacier (Miller, 1956); and by the dry climate with charac- teristic pine and other sub-arid vegetation found in the Atlin sector on the Canadian side of the icefield. H. Composite Considerations Some overall considerations of the specific observations and data from the main icefield sector are now discussed to facilitate future reference. . Higher elevation combined with a position geographically farther from the sea, are the prime factors responsible for a generally colder and more continental climate on the 5900- foot axial névé of the Taku-Llewellyn Glacier Complex. h? Englacial temperature investigations have shown that the crestal sector of this glacier system is geophysically 232: Temperate in character. In the firn of the highest plateaux the winter cold wave is partially retained through the summer months without being dissipated by seasonal increases in radi- ation, duration of sunshine, temperature, and summer melt- water percolation. This is in sharp distinction to the fully Temperate (isothermal) character of the glacier on the 125g; névc’s. Sub-surface temperature investigations in the crestal sectors also corroborate the recognition of a shortened ablation season and the effective reclaiming, at depth, of most if not all percolated surface water. The ablation seasnl on the crestal ne'véJL relative to the lower névé, is of less intensity as well as shorter duration. In 1961 it extended from approximately 5 June to 25 August, thus permitting prop- agated water to develop on the névé surface over a period of 2.7-months. The 1961 ablation season on the lower nave of the Taku Glacier extended from 25 April to 25 September...1.e. 5 months duration, or nearly twice as long as pertains on the crestal nave of this same glacier. A slightly longer ablation period is involved on the Lemon Névé due to its more maritime position...i.e. a little over 5 months duration. These ratios are roughly equivalent to those reported in previous records of the Juneau Icefield Research Program, over the years.l9h8- 60, and therefore are considered representative. Liquid water percolation in the crestal firn is of much h8 less volume than that produced on the lower nave, and does not find its way to the bottom of the glacier and drain off in subglacial drainage channels. Instead, it is largely re- claimed by freezing in the sub-freezing firn of the crestal zone. Therefore, on the upper plateaux, certainly above 5800 feet, there is little effective loss. 0n the Temperate, lowu' névé a substantial portion of the gross accumulation (estimat- ed from 60 to 90 percent) is reduced to runoff. From these considerations, it is clear that seemingly gradational climates can produce striking local differences in the regime of this icefield wherever it is characterized by multiple névés. Added to this is the probability that the gross meteorology of this entire region changes cyclically in 20-year to 90-year shifts, as suggested by Miller (1956, 1958). This would be revealed either by a warming trend or, conversely, by a cooling trend with its consequent lowering of freezing level. Thus by closely observing and delineat- ing these trends through sequential and systematic study of each component of the multiple ne’vé, fairly accurate forecasts may be possible in terms of the changes taking place in the physical characteristics of any sector of the icefield. For illustration one may visualize full glacial condi- tions...i.e. the general climate becoming significantly coldné for an extended length of time. This would mean that the whole geophysical character of the icefield would change. The lower neves would become sub-Temperate, sub-Polar, or even Polar depending upon the intensity and duration of the A9 colder conditions. In like manner, the geophysical character of the intermediate and crestal nevestaould also change to more Polar conditions. With the glacier becoming colder its creep rate would materially decrease. If the intensity of the cold phase increased to extreme Polar conditions moisune could not precipitate except by minimal hoar-frost sublimation, as under present conditions at the center of theGreenland Ice Cap (Victor, 1950). In such circumstances a corresponding decrease in accumulation would take place in those parts of the icefield so affected. The intensity and duration of the cold hemi-cycle could be of sufficient magnitude to diminish the mass transfer of ice from all of the main glaciers emana- ting from the icefield, and hence reduce the present névé re- gions to a state of equilibrium. The above hypothetic illustration of a complete change in climate is, of course, an extreme. It is not so extreme, however, that it could not happen; since it has happened in the glacial maxima of the Pleistocene. It is a condition which even today dominates the higher latitudes of the con- tinent of Antarctica. The other extreme case would bea warming trend resulting in complete ablation and destruction of the icefield. Through the development of local glacier conditions and inter-glacial landscapes, this also has happened. The present retracted icefield condition is but one link in the long chain between the cited extremes. In this the present regime of the Lemon Glacier is also considered part of the overall icefield con- dit ion e 50 Gross accumulation for 1960-61 on the crestal plateau has been shown to exceed 19 feet of firn while that on the lower ndve was in the vicinity of 17 feet. Net accumulation on the upper plateau at the end of the 1961 ablation season was meas- ured at l7p5 feet of firn (at densipy30.56, or 9.8 feet of water equivalent) while that on the lower névé was found to be approximately 5.7 feet of firn (at density 0.60, or‘3:g feet of water equivalent). Since 1950 recorded annual net accumulation on the crestal névé at the 5900-foot level has varied between 13 feet and 19 feet of late-summer firn (aver- aging lh feet). This suggests that the 1961 data represent somewhat higher than average values - not being exceeded in fact since l9h8-h9. These statistics are also compared with the crevasse-wall stratigraphy obtained in 1961. Thus, the suspected positive accumulation gain (not including diagenetic structures) over the past 15 years on the crestal plateau is in the order of 200 feet of firn-pack, or minimally 150 feet water equivalent. By including a 15-20 percent bulk increase due to diagenetic effects this figure may be advanced to around 175 feet of water.1 1. The total covering approximately the 16 years since the inception of this field research program in 19h6. III. GLACIO-HYDROLOGIC INVESTIGATIONS ON THE LEMON GLACIER The information described from the nevé studies in the main icefield area are now combined with available hydrologic statistics for an assessment of the dynamics and magnitude of runoff from the Lemon Glacier. Reference is made to runoff records for the decade 1951— 61 from a stream gauging site at the glacier terminus on Lemon Creek. By additional reference to the U.S. Weather Bureau climatologic data from coastal stations in the Taku District, and to the 1951-61 meteorologic records from icefield stations, an analysis is made of the effect of regional and local. cliJnatip ,factors on the glacio-hydrologic regime. This is followed by brief consideration of related geomorphic consequences. A. The Lemon Glacier Problem The Lemon Glacier, one of the smallest and most acces- sible glaciers of the Juneau Icefield, has been selected for this study because of its unique physiographic character. Although a distinct unit in itself, this glacier is juxtaposed to and southwest of the Taku-Norris Glacier system (Fig. l), and has a catchment basin not influenced or contaminated by drainage from this other system. The glacier is in a slowly recessional state with a trend in the decade of the 1950's toward an equilibrium condition (Crary, et al., 1962). 1. Total Runoff vs. Refrozen Percolation As we have already seen, the crestal plateau is charac- terized by sub-Temperate geophysical conditions; while the 51 52 lower nave is fully isothermal at 000. Thus, the great maj— ority of liquid water propagated during the effective ablation season at elevations below 5000 feet eventually is discharged as runoff. The Lemon Névé is essentially all below this ele- vation. In fact elevation-wise it is a small-scale counter- part of the lower névé of the adjacent Taku system. The mode and effects of liquid water generation on the Lemon Névé are thus similar to those on the lower névé of the main icefield. In consequence the overall geophysical character of the Lemon Glacier is also Temperate. In theory, most of the propagated surface water on a Temperate glacier percolates through the firn and drains to the base of the glacier through crevasses and fractures. It then eventually will pass off at the terminus via enclacial and subglacial drainage channels. It may be assumed, there- fore, that the volume and variation of free water discharged at the Lemon Glacier terminus is directly affected by the volume and variation of liquid water generated on its neve. 2. Areametric Relationships The relative position of the Lemon Glacier with respect to the main body of the Juneau Icefield is shown in Figure 1. Since the glacier is a separate system, being connected to the main icefield by a narrow divide, it has been regarded as a complete physiographic unit. This unit encloses an elongated basin 12.1 square miles in area (v. map, Fig. 27). It repre- sents an orographically simple catchment basin with practi- I cally all of the drainage derived from the Lemon Glacier Nave. Only a small fraction comes from surrounding valley walls. 53 The Lemon Glacier and its surrounding area have been map- ped to a scale of 1:63,360, again as shown in Figure 27. Its prime nevé lies roughly between the 3300 and hSOO-foot con- tours; with a mean elevation of about 3900 feet. This mean level corresponds with the mean elevation of the lower ac- cumulation nave on the main icefield. 3. Meteorologic Implications As previously noted, the 1961 summer temperature and pre- cipitation records from U.S.Weather Bureau sites at Annex Creek, Juneau City, Juneau Airport, and from the field site on the upper ridges of Mt. Juneau (precipitation only) have been plotted to provide comparison with the main icefield records in this reference year. Records encompassing the interval l9hl-6l, as obtained from the same stations, are also used to evaluate climatic fluctuations and trends, and to com- pare with fluctuations and trends in the runoff records. The coastal meteorologic stations are all within 20 miles of each other and bracket the Lemon Glacier on the west, south, and east (Fig. 1). Although all but one (Mt. Juneau) are near sea-level, this does not detract from the usefulness of the :records.. In the present analysis the coastal station data are interpolated, using correlative icefield data, so that reference to the 3900-foot névé of the Lemon Glacier can more effectively be made. The mean daily temperatures for Annex Creek,_Juneau City, and Juneau Airport have been presented in Figure 16 covering 51; the period 15 April through 10 October 1961.1 The mean daily temperatures for Camp 10, and the minimum daily temperatures for Camp 108, are also shown covering the respective periods of field occupation of these sites from July through September. The full scope of data graphed in Figure 16 represents a long- er period than the 5-month ablation season inferred for the lower icefield nave, but for reasons previously noted it may be considered close to the duration of effective ablation on the Lemon Glacier Névé. This may be cited as 5.8 months in 1961. Daily precipitation recorded at an elevation of 3576 feet on Mt. Juneau (Fig. 19) for the summer of 1961 is 3 to 5 times greater than that recorded at the coastal stations (Fig. 18), and 3 times that noted at Camp 10 in the equivalent per- iod (Fig. 9). The apparent reason for this has already been discussed in section IIGl. Since the Mt. Juneau data are con- sidered representative of statistics from the adjacent Lemon Glacier Neva, these precipitation records will be referred to with respect to that névé. Mean monthly temperature and precipitation (Fig. 20) are plotted for the period 1951-61. In addition, mean annual temperature (Fig. 21) and precipitation (Fig. 22) are plotted for the period 19uO-6l. These diagrams reveal the temperature and precipitation trends of the coastal stations and their 1. The original daily temperature and precipitation records are referenced in Appendices 28-30 for the coastal stations. SS variations with respect to each other.1 By reference to Figure 21, the ll-year running mean of annual temperatures, commencing in 1950, show a slight but steadily decreasing trend continuing through 1956. This then reverts to a steadily increasing trend up through 1961. The ll-year running mean of January temperatures over the same years (also Fig. 21) reveals a decreasing trend continuing up to 1959 and then reverting to a possibly significant trend of increasing temperatures. From these two sets of data it would appear that the low temperature years out of the past decade were in the interval l956-59-—-a seemingly paradoxical relationship in view of the maximum radiation intensity dur- ing the 1957-58 period of the International Geophysical Year. The mean annual temperatures (Fig. 21), however, show an in- crease during this period. Further discussion of this matter will be made at the end of this section, after consideration of the total precipitation trends over the decade of the '50's. As for the precipitation records, the annual fluctuations and trends remain generally similar for Juneau City and the Juneau Airport from 19h0 through 1961 (Fig. 22). Juneau City, however, is consistently 63 percent higher, as illustrated by the plot of 11-year running means of annual precipitation. Such differences in precipitation over distances of less than l. The mean monthly temperature and precipitation data for the interval 1951-61 at the coastal stations, from which records these diagrams have been prepared, are given in Appendices 31-33. The mean January and mean annual tem- perature and precipitation records for these stations are listed also in Appendices 3h and 35. 56 10 miles are strictly orographic. This factor is further illustrated by the Annex Creek data. The Annex Creek record over the comparable period of 11 years, in fact, shows a good deal more differentiation than the record from the Juneau and Juneau Airport stations. The mean annual precipitation curve (Fig. 22) dipped the lowest in the years between 1950 and 1955. and shows a marked rise from 1956 to 1961. The 11- year running mean of annual precipitation for Annex Creek (also Fig. 22) indicates a similarly pronounced decreasing trend continuing from 1950 through 1957, with a subsequent leveling off up through 1961. These data reveal dramatically that Annex Creek receives a considerably greater percentage of precipitation than Juneau City; the percentage decreasing steadily, however, from 33 percent in 1950 to u percent in 1956 through 1961. By again consulting the mean annual curves in Figure 22, one can see that precipitation at the Juneau coastal stations has been steadily increasing since 1957, with this same in- crease reflected at Annex Creek since 1955. It is noteworthy that this trend continues to rise through 1961. Also by con- sidering the mean monthly precipitation plots (Fig. 20) it is evident that beginning with 1956 the fall and early winter months experienced generally increased precipitation with a most prominent rise taking place in 1961. This correlates with the culmination of the increasing trend of mean annual precipitation during the referenced 5-year interval (Fig. 22). It also correlates with the general rise in mean annual S7 temperature shown in Figure 21, and with the pronounced down- ward trend in mean January temperature indicated in this same figure. The long-term seasonal trends thus appear to be com- plex, possibly involving a lag correlation, the discussion of which is beyond the present purpose.1 h. Discharge Statistics Because the Lemon Glacier and its drainage basin are a complete physiographic unit, essentially all of its drainage is channeled into Lemon Creek above the stream gauging site.2 The glacier terminus rests at an elevation of 1500 feet above mean sea-level. The gauge elevation is at 600 feet above mean sea-level. Its position is 6000 feet down-valley from the point where in 1961 the subglacial drainage channel dis- charged water from the terminus. Therefore, this volume of water passing through the hydrograph station represents es- sentially complete drainage from the glacier basin. The topography of the basin and glacier itself, and the position of the gauging site, are indicated on the map of Figure 27. This map has a contour interval of 100 feet. Figure 23 diagrams the mean monthly discharge at the 1. Miller (1956) has pointed out the problem of thermal lag effects in the climatic cycle. He suggests that they may relate to the retention of heat in the oceanic waters a- long a coast. Some degree of lag is of course a natural consequence of the considerably higher specific heat of water when compared te.the atmosphere. 2. Established by the U.S. Geological Survey in the summer of 1951, on recomendation of the Juneau Icefield Research Program. 58 gauging site, in cubic feet per second. The plotted record extends over the lO-year interval between October 1951 and September 1961, and is based on the original data listed in Appendix 36. The form of this discharge curve is generally sinusoidal. Particularly notable are the rapid increases and decreases in discharge rate between summer and winter. In the annual segments of the Figure 23 curve occasional jogs occur, representing minor but notable fluctuation during October and November (note especially the curve segments for the years 1956-57 and 1957-58 as well as the interval 1960- 61). A prominent fluctuation can be noted in November 195h matching that of November 1956, and January 1958. The autumn anomalies are probably due to surges of increased rain and melt-water resulting from the violent autumnal storms which characterize this coast. Furthermore, by comparing Figures 20 and 23, the autumn anomalies are seen to correspond with significant increases or decreases in temperature and pre- cipitation during the corresponding months of October and November in these particular years. The January 1958 anomaly , however, deserves special consideration. This month was characterized by considerably higher temperature and precipi- tation than its bracketing months of December and February. It is significant that such increases do not normally occur in the January records. The causal factor would appear, therefore, to be primarily the occurrence of unusually high temperatures in January of this year (Fig. 20). The period of greatest liquid-water generation indicated by the period of maximum flow in the mean monthly discharge 59 curve (Fig. 23) extends from mid-April to mid-October. This suggests a 6-month interval of significant drainage which agrees closely with the 5.8 month effective ablation season inferred for the Lemon Glacier. ' .The mean monthly and mean annual discharge rates plotted for 1951 through 1961(Figs. 23 and 2h) indicate unquestionable trends. Figure 2h shows the mean annual trends based on the water year (October to September) as well as the calendar year. The discharge is seen to increase from 1951, with a drop-off to reduced discharge in l95h-55, and then an irregula‘ rise continuing from 1955 up through the period of this study in 1961. These trends are shown even more strikingly in the plot tinge of mean annual maximum and minimum discharge given in Figure 25.1 Here the minimums exhibit only a slight in- crease from 1952 through 1956, corresponding to the reduction in annual discharge cited above. From 1956 through 1961 the mean minimum values increase dramatically again corresponding to the marked increase in annual discharge noted above. The mean annual maximums express a more varied picture but, over- all, show an increasing trend which parallels the mean annual discharge curves of Figure 2h. The noteworthy upward discharge trend in recent years is not unexpected. It has already been demonstrated that temper- ature and precipitation trends since 1955 have been sipificmtly 1. The original data of Lemon Creek en mean annual maximum and minimum discharge rates, 1952-61, are tabulated in Appendix 37. 6O upward. In a strongly maritime climate where melting and rainfall are intimately related to temperature, runoff trends should also show a comparable increase. Consideration is now given to the mean daily runoff curve (Fig. 26) graphed from the data for 1961 listed in Appendix 38. In this, comparison can be made with the histograms of daily precipitation for Juneau City, Juneau Airport, and Annex Creek (Fig. 18), and for Mt. Juneau (Fig. 19). It is immediately apparent that the peaks of discharge in the 1961 record correlate almost directly (a slight but expected lag is apparent) with peaks of rainfall. We are reminded, however, that the main icefield investigations have shown that melt-water also plays an important role in the pro- pagation of available liquid water. By comparing the ablation record at Camp 10B (Fig. 9) with the mean daily runoff curves, however, the correlation is found to be extremely poor. The ablation curve does not trend to a significant peak or trough during the period of record. Daily fluctuations may be detect-‘ ed, but these are not as notable as in the precipitation curves. It is pessible that comparison with ablation measure- ments made directly on the Lemon Neve would show a closer re- lationship, but regardless the conclusion appears unavoidable ...i.e. that on the Lemon Glacier precipitation dominates in governing the form of the mean daily runoff curve. A plot showing runoff from melt-water alone (without being contamina- ted by precipitation)wou1d in all probability be much smoother than the one shown in Figure 26. Another implication of this 61 conclusion is that the capillary retention capacity of the firn-pack is sufficient to impede the development of strong surging at the volume levels involved in melt-water generation. Support for the preceding conclusion is given by some pertinent statistics. The total runoff for the month of Aug- ust 1961 is 68.u inches of water.1 Over the same period the total rainfall on the Lemon Glacier basin (as interpolated from the Mt. Juneau records) was 52 inches.2 Ablation over a comparable 31 day period in the mid-summer of 1961, as meas- ured on the lower néve of the main icefield, is calculated as 25 inches water equivalent. When extrapolated to the Lemon Glacier basin, the total precipitation plus ablation for the month of August 1961 would be 77 inches, a figure remarkably close to the measured runoff, 68.u inches.3 On the assumption that this is close to a true value, the difference may be ex- plained by the amount retained in the firn-pack through capil- lary force. Miller (1962a) has shown that up to 15 percent of the density increase in the summer firn on the Juneau Icefiehi is due to capillary retention. Thus, these figures, represent4 ing a difference of 12 percent, may be corroborative. The foregoing analysis can be extended into the preceding 1. Calculated in inches to compare with the water equivalent statistics for ablation and precipitation. 2. h9.7 inches plus two days of missing record approximates 52 inches. See Appendix 27, for the Mt. Juneau precipita- tion records. 3. Measured value obtained from the Lemon Creek 1960-61 dis- charge data office file of the U.S. Geol. Survey Water Resources Division, Juneau, Alaska. 62 month of July 1961, in which the monthly precipitation was 33.9 inches. With the extrapolated ablation again being 25 inches, the total calculated volume of available propagated water equals 58.9 inches. The measured value of discharge at the stream-gauge site for July was 53 inches. The dif- ference in this case is 10 percent, which is also in line with the aforementioned ratio of capillary retention. For other reasons too, calculated values should be higher than measured values. Not all of the precipitation falling on the side-wall sections of the Lemon Glacier basin is going to result in runoff. A portion will be assimilated by vegeta- tion and soil, Just as in firn of the glacier. Evaporation, although probably slight, also claims a share of the precipi- tation, particularly from bedrock exposures. But most impor- tant is that volume retained in liquid form by capillarity of the firn and by impoundment in crevasses and other open frac- tures. The combined effect of all of these various factors would seem to explain the differences which have been cited between total volumes of propagated water and total measured runoff. From the above statistics the total propagated melt-water through ablation on the Lemon Glacier Nevé may be assumed to account for anywhere from 30 percent of the total runoff in the summer to nearly 100 percent in the winter (see discussion below). Furthermore, the form of the runoff curve (Fig. 23) demonstrated how approximately 80 percent of the total annual runoff occurs during the ablation season; with the remaining 63 20 percent taking place in late fall, winter, and early spring. Thus, the combined effect of ablation and rainfall on the annual discharge pattern is well substantiated. The thesis that melt-water constitutes most of the runoff during winter is of special interest and deserves further dis- cussion. Winter precipitation of the solid form...i.e. snow- contributes little to the runoff so long as temperatures remain below freezing. On the other hand, melt-water,stored in a glacier during the summer percolation period, and permitted to remain in liquid form km? the Temperate geophysical condi- tion, appears to be steadily discharged in small volumes (Miller, 1956). In this situation one must assume that there is slow continuation of percolation to greater depths from the capillary retention zone which is penetrated by the winter cold wave. This percolation, abetted by increased compaction squeezing of interstitial water from between the firn crystals, provides a continuous source of drainage throughout the winter months. It is also probable that continuous and discontinuous movements within the glacier produced by the stresses of a thickening winter snow-pack release water trapped during the summer by layered and diagenetic ice structures. In addition, some melting at the base of the glacier from the effects of geothermal heat may contribute minor amounts of liquid. Even though the ambient air temperatures are below freezing in whuer a glacier can act as a thermal insulator and thereby keep it- self, and its deep englacial reservoirs of liquid water, pro- tected from seasonal atmospheric extremes. 61+ It is significant that the winter runoff, in contrast to the summer's, is not laden with glacial sand and silt. This further connotes the presence of a statichcapillary reservoir rather than a supply by flushing of rain-water. Such clear water discharge in winter may, in fact, provide excellent opportunities in the future for direct use of un- treated runoff in commercial and municipal applications, such as would not be possible during the summer months. B. Special Considerations 1. Potential Effects of Climatic Changg As far as the dominant factor, climate, is concerned most of the records appended in this dissertation are of insufficient duration to serve as a basis for specific forecasts of hydro- logic changes or fluctuations. Sufficient data are given, however, to verify the trend in the past decade toward in- creasing maritimity in the coastal sectors of the Juneau Ice- field and, by inference, in all of coastal Southern Alaska. The continuing rise of annual temperature and precipitation during the most recent decade is causing, as has been shown, an increase of runoff in the area affected. If this trend were to continue for many decades (in effect raising the mean freezing level higher than the nevé itself) the ultimate re- sult would be complete removal of the firn—pack and reduction in total area of the Lemon Glacier. Attending this would be a decrease or even eventual disappearance of the propagated melt-water component of runoff, which would in turn diminish or even totally eliminate the discharge over the winter months. At present, runoff along the periphery of the Juneau 65 Icefield may be near its 20th century maximum, or possibly will attain this maximum within the next few years. With warmer climate and increased precipitation always comes the prospect of worsening flood conditions in these mountainous districts. Typical danger spots in the region of this study are the Tulsequah, Taku River, and Berners Bay sectors east and north of Juneau. Another well-known locality is Lake George on the Knik Glacier of the Chugach Range. These sites are prototypes of catastrophic seasonal glacial floods. ther districts too may develop flood problems as runoff reaches its peak. Thus, recognition of relationships of the kind here considered have practical value in addition to their academic geomorphic and climatologic implications. The present trend appears to be due to change within the next several years, since the thermal curve plotted over many decades has been seen to be sinusoidal. This suggests a cor- relation with the sunspot cycle which has a dominant wave length of 80-90 years, with nodes of high and low sunspot activity separated by approximately AS years (Miller 1958, 1962b). Reference is made to the 1958 paper cited above in which a comparison of sunspot numbers, climate, and glacier behavior is shown. In 1917 the mean January temperature curve recorded at Juneau was at its low point and has been on the rise up through 1961. This corresponds with the current hemi- cycle of increased sunspot activity. In terms of the h5-year half cycle, climate should presently be ready to revert to colder trends, as in the next few years we enter a period of 66 lesser sunspot activity. The resultant lowering of freezing level to minimal limits in alternate hO-SO year periods would cause a thinning of glaciers nourishedzat high elevations and a thickening of glaciers with prime neves at low elevations. This should also reduce total annual runoff by lengthening the winter season and by shortening the effective ablation season in the warmer months. Abetting this condition we might antic- ipate contemporaneous reductions in precipitation and ablation, such as have been demonstrated to accompany colder conditions. 2. Hydrograph Anomalies On a number of the daily hydrograph curves for Lemon Creek which were examined in the files of the U.S. Geological Survey Water Resources Division office in Juneau some surprisingly sharp short-term peaks were observed, indicating sudden high- velocity surges of runoff. Little indication of these abnormal peaks is found in the published daily records, such as have been plotted in Figure 26. This is, of course, the result of averaging runoff values over a 2u-hour period. Other peaks are also seen on the curves of daily record, but these are of longer duration...i.e. lasting up to several days. They are presumably the result of significantincreases in precipitation over intervals greater than 2h hours. The abnormal short-term peaks, however, show no direct correlation with ablation or meteorologic fluctuations. As such they are an anomaly worthy of special consideration. It is furthermore doubtful that they are the direct reflection of precipitation changes, since precipitation in this region could not cause such large increases in volume over such short pemods 67 of time. The slow build-up of ablation melt is also not con- sidered sufficient to produce such effects. In fact, a minor catastrophic event is believed essential to explain these short-lived and greatly-increased volumes of flow. Indirectly, the combined effects of rain and melt-water could be a cause...i.e. through the impounding and storage of rain and melt-water. It is a unique characteristic of Tem— perate glaciers, through rainfall and copious melt-water gen- eration in the summer season, that they become saturated at depth and develop what is essentially a water table relation- ship. Such a water table has been measured by Miller (1962a) on the lower nevé of the Juneau Icefield. Because of this, crevasses extending below the water table and pinching out at depths of 90-120 feet often hold large quantities of impounded water. It seems quite possible, therefore, that a single Luge crevasse, or a system of such crevasses, could rather suddenly be extended by the periodic strain release of englac ial stress. The relatively steep gradient of the Lemon Glacier ter- minal area (Fig. 27) with slopes of 5°to 20°, should lend it- self to spasmodic surges in strain-rate. In shallow or thin ice this might even be expressed by crevasses extending them- selves to the base of the glacier. With impounded water in such fissures the consequence could be catastrophic. Upon extension of even one such fracture into the basal zone of the glacier, impounded water could he suddenly released as tor- rential runoff. The nature of this release, however, would be such as to increase the volume of flow of Lemon Creek over only a very short interval. The sudden release of impounded ., 68 water by the extension of fissures at the bases of crevasses has been observed in the Camp 10 sector of the Taku Glacier, and also reported on the Skautbreen in Norway (McCall, 1952). In the present case, of course, a tectonic mechanism must remain hypothetic since it would be difficult to witness the event taking place. Such, howeven does provide a plausible explanation of the completely anomalous surges indicated by the stream-gauge record. In this record the possibility of an alternative climatologic cause is minimized when comparison is made between the plotted curves of temperature, precipita- tion, and runoff. In no wise do these suggest that even the most abnormal climatic fluctuations of the region can directly produce such instantaneous peaks. It is reiterated that these peaks are not the same as the patterned cycles of discharge, which have been previously discussed, but are aperiodic surges of drainage of short duration. Regardless of the cause of the sudden small-scale outbreaks, it is clear that Temperate glaciers exhibit a self-releasing capability whenever hydro- logic stresses reach certain critical limits. 3. Periodic Large-Scale Floods Mentioned earlier were several locales where catastrophk: floods of large size occur. In the Taku District the Tulsequah1 flood is the best known (Kerr, 193k). Forty miles northeast of Juneau on the eastern margin of the Juneau Ice- 1. The glacier, river, and lake named "Tulsequah" are also sometimes known by the name "Talsekwe," a form, however, no longer used in official Canadian publications. 69 field in British Columbia, an ice-dammed lake is formed agakmt a lobe of the Tulsequah Glacier (Fig. 1). This lake period- ically drains each summer, sometimes twice a summer, in July or August. The lake drains in h or 5 days, discharging some 60 billion gallons of water on the Tulsequah River and Taku. River flood plains. Most of this drainage occurs during a h8-hour period (Marcus, 1960). The lake itself is the result of seasonal impounding on a far grander scale than the fissure-type discussed in the previous section. But the catastrophic outflows are a result of geomorphic and hydrologic controls. What happens at the ice dam to cause sudden releases of the lake water into the Tulsequah River is still not clear. Several hypotheses have been put forward but it seems none have been satisfactorly proved. Yet, this problem is of economic importance since for many years the flood washed out a $15,000 bridge, which had to be re-erected annually across the Tulsequah River by the Con- solidated Mining and Smelting Company of Canada, Ltd. The meteorologic, ablation, and runoff data from the Juneau Icefield give no direct hint as to why the drainage of Tulsequah Lake is in the form of catastrophic bursts. The volume of rain and melt-water forming the lake appears to reach a critical stage at which time the flooding takes place. It is apparent that a gradual build-up of hydraulic head oc- curs as a result of the impounding of these waters behind the ice dam. The mechanics of the release of this stress, result- ing in the sudden out—flow of water apparently through 70 tortuous subglacial channels, is the unresolved problem on which detailed on-the-spot observation is needed. Once the mechanics are satisfactorily understood, then ablation, pre- cipitation, and runoff measurements may be conducted in the Tulsequah sector of the icefield to permit forecasting of future floods. This potential research could also point the way to corrective action in controlling such outbursts in districts where human habitation, mountain highways, and omnr lines of communication may be threatened. It is of interest in this connection that a large number of other self-discharging glacial lakes are present in the Alaskan Boundary Range about which glacio-hydrologic informatkn is completely lacking. Other examples of these in the Taku District are two large ice—margin lakes located northwest of the icefield and dammed by the Gilkey Glacier in the Berners Bay Trench (Miller, 1952b). Without any obvious outlet these waters are suddenly released late every summer to crest in sub- stantial floods in the Antler River Valley 15 miles down ghmfin' from the impounding locale. Across the Antler River, as well as in the valley of the Taku River, highways eventually will be constructed to reach Alaska's capital city of Juneau. In this district alone much information will be required on the nature and periodicity of large-scale glacier-born floods. IV. OTHER GEOMORPHIC CONSIDERATIONS The unique internal constitution of glaciers and their related hydrologic regime involves other characteristics of potential economic importance. For example, there is the potential reservoir capacity of future significance, not with respect to liquid water but to the considerable volume stored in frozen form. Then there are aspects of erosion and sed- imentation produced by the glacio-hydrologic forces which can have practical value. Some of these are now briefly considered. A. Potential Glacier Reservoir Capacity . A glacier, being a body of water in the form of firn, ice, and varying amounts of the liquid component depending upon its geophysical character, is a natural open system relinquishing part of its substance in summer and replenishing the supply in winter. In effect it is a huge mass-energy-time system, the economic potential of which has hardly yet been exploited by man. The reservoir capacity of a glacier can be determined by measuring its surface area and the thickness and physical characteristics of both firn-pack and ice. Firn and ice depdm and related information can be revealed by test-pit, bore-hole, and geophysical measurements. As we have seen, consideration can also be given to the liquid-water content of the firnepnk. By these means, volumetric limits of the glacier, its water storage ability, and its total water equivalent can be readily calculated. Of course, a glacier in a given region is controlled 71 72 largely by meteorologic conditions and therefore, may shrink or grow depending upon fluctuations of climate. Since, as far as man is concerned, these are relatively long-term changes, we need not be unduly concerned whether the glacier in questkn is in a fairly healthy or an unhealthy state. But by obtaining systematic quantitative data on the annual budget through yearly measurements of accumulation, ablation, and meteorolqfic data such as have been dealt with in this dissertation, it is possible to prognosticate the hydrologic behavior of glaciers, upon which economic planning can be based. B. Practical Aspects of Erosion and Sedimentatigg An actively advancing glacier with substantial forward movement causes a great deal of erosion along its bed. This erosion is exemplified by direct plucking and abrasion of the rock surfaces over which the glacier moves. Some erosion is also produced by the torrential subglacial drainage streams, and by side-wall frost shattering in open spaces. The ulthnda result is the deepening and molding of the glacier's bed into a trough of usually U-shaped form. Most of the rock directly eroded from the bed is reduced to rock flour...i.e. glacial silt and clay. This material is eventually washed out by the subglacial and proglacial streams and deposited somewhere down valley. In the case of the Lemon Glacier, rock flour is trans- ported by Lemon Creek directly into the adjacent fiord (Gastineau Channel, Fig. 27). This presents a problem since the silt brought in by Lemon Creek and other glacial streams no. 73 (e. g. the adjacent Mendenhall River) is filling in the northern section of this channel. In recent years continuous dredging has been required to keep the channel clear,,even for small boats to navigate. Furthering this condition is the post-Wisconsinan epeirogenic uplift of the Juneau area at the mean rate of 1.5 centimeters per year; a total of 500 feet since maximum glaciation (Twenhofel, 1955). The resultant uplifted and poorly drained silt beds are now the locations of many farmlands along the Alaskan Coast. In the Juneau area they serve as grazing grounds for the only herds of dairy cattle in this region. The geomorphic and tectonic processes involved in the production of these features insure an in- crease in the use of such lands for farming purposes in the years ahead. Another sedimentation problem is the silting in of natural and man-dammed lakes. An illustration in the Taku District is Salmon Creek Reservoir, about three miles north of Juneau “Mg. 27). This lake is used by the city of Juneau for a hydro- electric power source and municipal water supply. It is grad- ually being filled in with glacial fines by feeder streams from two small local glaciers. Theoretically, this process could cause the lake to eventually overflow its boundaries, thereby Jeopardizing the municipal and hydro-electric water programs. This type of sedimentation process is of little concern at present but in the future could become a major problem in the expanded development of hydro-electric power and municipal water reservoirs along the Alaskan coast. 7h Another economic aspect of these studies bears on glacial erosion. The mountains of the Boundary Range and adjoining districts of Alaska and northwestern Canada are famous for their gold mines of years ago. Glaciers, by down-cutting and eroding into the metamorphic bedrock, originally exposed gold veins and lodes. Through mechanical weathering and glacial corrasion the gold was separated from the country rock and because of its high density, settled into the beds of glacial streams and became concentrated in glacially-eroded depressions Upon retraction of the glacier it awaited discovery by the ever-searching prospector. In the Alaska-Juneau gold belt it was such placer gold deposits which were initially discovered, leading to the ex- tensive mining of the parent lodes in the early decades of this century. In effect the glaciers were the first miners. No doubt, there are other signifiaum deposits yet to be found in the auriferous sediments washed out and deposited by runoff from these glaciers. C. Water and Hydro-Power Projects The Salmon Creek Reservoir discussed earlier is in truth, a man-modified tarn, impounded in an early Wisconsinan glacial cirque (Miller, 1961). There are many of these natural basins in the Boundary Range of Southeastern Alaska. Some contain terns fed by glacial streams, others are dry. The potential can be seen for low-cost development of such basins and tarns as local reservoirs providing future power and water. Such has been a problem with respect to the recent multi-million 75 dollar pulp mills at Ketchikan and Sitka, and may arise as a future problem with respect to a large pulp development which may be considered at Juneau and elsewhere in this region of Alaska and Canada. In such cases the silt problem can became an especially important consideration. This, not only as an infillent of the reservoir but also as a contaminant of the water itself. Lake Atlin, which lies 65 miles north of Juneau, is a prime example of a potential major source of hydro-electric power. This lake, which lies entirely within Canada, is nour- ished by the runoff from the continental flank of the Juneau Icefield. It fills a deep glacier-carved valley 75 miles long and from 2 to 5 miles wide. If jointly developed by the United States and Canada this lake could supply the low-cost power and water needed to attract large-scale industry to this re- gion. What this would do for the future of Southeastern Alaska and Northwestern Canada is obvious. Unfortunately, however, Lake Atlin is in a region sparsely populated, completely unde- veloped, and not even fully explored. The future, however, will see changes in this situation, since such vast hydro— resources cannot forever remain undeveloped. When that hap- pens the potential power and water supply of Atlin and its sister lakes will be high on the list, just as the Hoover, Grand Coulee, and Niagara-St. Lawrence power projects became necessities for continued municipal and industrial develop- ment. Thus, looking ahead to such a time, glacio-hydrologic studies on the Juneau Icefield will be given similar priority. V. SUMMARY AND INTEGRATION OF RESULTS Aiflnal compendium of the results of this study is given below. This summary may be considered as a detailed abstract of the 1961 results where they concern investigations of the main crestal neve and related aspects of propagated surface water and runoff. Statistics particularly significant to the long—term studies of the Juneau Icefield Research Program are underlined. A. Brief of the Neve Investigations 1. During 1961 the crestal neve of the main Taku Glacier on the Juneau Icefield was found to be sub-Temperate in geo- physical character, as compared to Temperate conditions pre- vailing in the m§in lower neve. At 5800 feet to 6500 feet the magnitude of sub-freezing was measured at -O.h° to -O.9”C at depths of 10 to uO feet beneath the 1961 ablation surface, and -O.95C to -O.lO°C at depths from 50 to 150 feet. 2. Net accumulation for the 1960-61 budget year on the crestal nevé was found to be 17.5 feet of firn, and on the lower neve, 5.7 feet of firn (water equivalents noted below). The 1960-61 crestal firn-pack ranged in density from 0.50 gm/cc. at the surface, to 0.58 at 15 feet. The basal depth- hoar stratum was of a density 0.52 at 17 feet. The resultant bulk density, including the addition of diagenetic ice, was determined as 0.56. The resultant water equivalent for the 1960-61 firn-pack was 9.8 feet of net accumulation on the u er neve. The corres ondin water e uivaIEfit—fer the lower ngve firn-pack (EuIE density %.505 was 3.5 feet for the 1960- 61 budget year, including the proportiOn 6f diagenetic ice. 3. The 1961 ablation and temperature records bear out previous reports of a much shorter_ablation season on the crestal neve than on the lower nevé. The duration of the effective ablation season for 1961 was 2.7gmonths,(5 June- 25 August) on the crestal neve at the mean elevation of_5§00 feet; and months (25 April - 2 September) on the lower nave at the mean elevation of §9§O feet. The Lemon Névd“ ablation season at’a comparable mean elevation of 3900 feet was found to be of 5.8 months duratiOn in 1961. h. Minimum values of gross ablation in the 1961 budget year at the mean elevations o e cres a1 and lower nevés were calculated respectively to be 1.5 feet and 6.3 feet water equivalent. 76 77 5. Propaggted surface water percolating into the crestal firn was ftund largely to be reclaimed at depth in consequence of the observed sub-freezing glaciothermal conditions. This verifies under present conditions the findings of the early 1950's that gross ablation on the upper néve must be considmed as recaptured accumulation. Therefore, net ablation en the crestal neve is reported as essentially zero. On the lower neve most of the propagated surface water percolates through the glacier becoming runoff at its terminus. A small amount of this water, however, freezes in the firn-pack during the early part of the ablation season while the winter cold wave is still present. Thus, annual net ablation on the lower neve by volume is slightly less than gross ablation. 6. The mode of melt—water percolation involves concen- tration of water in "channelized" zones...i.e. selective in- filtration in which the direction and rate are guided by ice structures, rather than being characterized by a uniformly descending front. 7. The 1960—61 crestal and lower neve firn-packs con- tain similar diagenetic ice structures (strata, laminae, lenses, and columns) but on each have these differ in volume percaxage. a. Diagenetic structures constitute a 5 percent increase in density in the crestal firn and an approximately 8 percent increase in the firn-pack of the lower neve. A component of diagenetic ice comprised of vertical "columns" was abundantly noted in the firn of the lower neve while bein relatively scarce in the 5900-foot crestal firn. 0n the g500-foot phfimau of the Gilkey Neve, however, these were found in even greater abundance than on the lower (3900-foot) neve. This is attrib- uted to the’stronger maritime influence exerted on this sub- temperate neve by air masses sweeping up the Berners Bay Trench into which the Gilkey Glacier drains. b. Diagenetic ice structures are formed by the freezing of propagated surface water. Those found in the firn of the lower nevé are formed only during amelioration of the firn at the beginning of the ablation season, and to a far lesser extent during the brief interval of transition at the onset of the cold wave in early autumn. Because oft:he persistent sub-Temperate englacial conditions those of the crestal neve form throughout the ablation season. 8. Glacio-chemical analyses made of the Juneau Icefield firn reveal a gradfial decrease in NaCl inland from the coast. The sampling, however, was insufficient in areal extent and time to. corroborate the working hypothesis concerning shifts in climatologic and accumulation effects. But they do bear out the relative continentality of the crestal neve and maritimity of the lower and Lemon Neves. Also, they point the way to fruitful future results in the interpretation of firn profiles from depth. 9. Interpretation of the Lemon Glacier meteorology is 78 permitted by access to continuous weather records from stations at adjacent locations. 8. The temperature range on the Lemon Neve (mean elev. 3900 feet) is found to be similar to that on the lower neve of the main icefield; although somewhat warmer due to its slight- ly more maritime position and lesser influence by katabatic icefield winds. By extrapolation from available data the Lemon Neve was found to experience a 5.8-month effective ablation season during the 1960-61 regime year. Assessment of the runotttdata over the decade since 1951 corroborates this as a representative valhe. ’ I b. Total precipitation (water equivalent)on the Lemon Neve is considered to correspond to that at the rain-gauge site (3576 feet) on Mt. Juneau. This is approximately triple the preqipitation recorded at equivalent elevations on the lower neve of the main icefield. Orographic factors, coupled with geographic position, account for this difference. B. Brief of the Glacio—Hydrologic Investigations 1. Consideration was given to climatic trends covering essentially the past decade; and using data from the Annex Creek, Juneau City and Juneau Airport stations. a. The ll-year runningfimean of annual temperatures for these stations exhibits decreasing temperatures ftom 1950 to 1956; with the trend increasing from 1956 through 1961. The ll:year running_mean of Januagy temperatures reveals a marked decrease from 1950 through 1958. In 1959 the trend reversed to increasing temperatures continuing through 1961. It shaihi be noted, however, that the overall trend of January temper- atures at Juneau since the 1917 low point has shown a general increase through the present period of record; with the rever- sal of the past decade probably representing a superimposed fluctuation. Since this study is primarily concerned with regime changes over the interval 1951-61, consideration of the longer-range upward trend is beyond the scope and purpose of the present treatment. b. With regard to precipitation the 11-year runnigg mean of annual total precipitation at Juneau City and Juneau Airport shows generallyvlittle change over the period 1950* through 1961. The ll-year running mean of annualgprecipita— tion for Annex Creek, however, reveals a pronbunced decrease from 1950 through 1957, the curve then levelling over the 5- year interval 1957-61. c. Comparison of the mean annual precipitation records, however, shows a gradual increase since 1957. Also, the mean monthly precipitation data reveal an increase in autumn and early' winter precipitation since 1956. These trends are of importance in the analysis of Lemon Glacier discharge data. 2. Hydrograph records of mean annual discharge rates of runoff from the Lemon Glacier basin show a gradual increase over the decade 1951-61. The trend parallels the previously cited increase in annual temperature and precipitation values 79 since the mid—1950's. It may reflect as well the longer-term warming shown by the upward trend of winter temperatures over the past uh years. The mean monthly discharge rates tend to corroborate a 5.8-month ahlation season on the Lemon Neve, since in the period April-October approximately 80 percent of the yearly discharge occurs. Precipitation and not ablation generally governs the magnitude of fluctuation in the mean daily runoff curve. The greatest peaks of runoff are due tdtfluctuations in precipi- tation; ablation being characterized by relatively small var- iation throughout the summer months. 3. Calculated runoff from the Lemon Neve for July and for August, 1961 was respectively 58.9 and 77 inches. This is compared to a measured runoff of 53 and 68.h inches for these two months. The significant differences between cal- culated and measured runoff are considered due to retention of some melt-water and precipitation by the capillary inter- crystalline forces in the firn, by impounding in crevasses and to a much less extent by absorption in the soil and veg- etation of the basin rim, and by evaporation. h. The preceding summer's rain and melt-water is con- sidered to be indirectly responsihle for runoff during the winter period. Most of this is stored in the glaCier during the ablation season, then subsequently discharged in small and steady volumes. The discharge is relatively free of glacial silt during the winter months, which further implies origin in the preceding ablation season. 5. Meteorologic data covering the decade 1951-61 indicate a trend toward a slightly more maritime climate in the Juneau area. 6. Based on Lemon Glacier hydrologic records since 1951, runoff in this decade has steadily increased andL through anal- sis of the climatic trends, should_peak in the next few years. ter that the trend should reverse, paralleling deereases in temperature and precipitation associated with an indicated short-range reversal in the climatic cycle. 7. Discharge anomalies in glacier runoff are character- ized on the Lemon Creek hydrograph charts b notably sharp peaks of brief duration “ifbw hours or less). These peaks are probably the result of sudden releases of impounded water held in crevasses and associated fissures in the Lemon Glacier at depth. The events may be triggered by normal glacier creep, or associated discontinuous movements causing deepening of crevasses or extension of fissure systems into the basal shear zone of the glacier. Here further drainage is probably aided by fracture permeability and the presence of related subglacial channels. 8O 8. The annual Tulsequah floods, originating on the east- ern margin of the Juneau Icefield, as well as similar glacier bursts in the Berners Bay sector to the north, are considered direct results of geomorphic, glaciologic, and hydrologic con- trols. Once the mechanics of associated stress-strain in the impounding ice is understood, forecasts of future ice—released floods which threaten site of human activity may be made by application of selective meteorologic and runoff data of the type considered in this present report. Remedial measures may also be taken to release the lake waters slowly. C. Review of Practical Glaciologic Considerations 1. A glacier may be considered as a natural reservoir of co-existing liquid (in the Temperate case) and frozen water. Its liquid storage capacity and total water equivalent can be calculated through area and thickness measurements of the snow- pack and firn—pack, and of the underlying mass of bubbly and dense glacier ice. Allied measurements can be made of its structural and glaciothermal character and of the volume of stored liquid water. The evaluation of related meteorologic and glacio-hydrologic data may aid in the assessment of res- ervoir capacities and the forecast of discharge volumes for future commercial and municipal use. 2. Sedimentation of glacial erosional products under certain circumstances have costly effects. The eroding power of an advancing glacier is great. Abrasion at the sole of a glacier produces vast quantities of rock flour. As illustrat- ed by the Lemon and Mendenhall Glaciers, such fines are car- ried by discharge streams into the Gastineau Channel. Depo- sition there has in-filled the northern section of this fiord, so that dredging has become necessary to keep it navigable. Abetting this effect has been 500 feet of post-glacial upwarp in this sector of the Boundary Range since maximum glaciation in the Pleistocene. 3. One beneficial aspect of glacial erosion and sedimen— tation is the de ostion of lacer gold in outwash streams, in depressions of the floor 0 glacial valleys, and in abandoned cirques at low and intermediate level. The gold, originating in veins and lodes. has been extracted from the country rock by shattering, plucking, and abrasion by periodically advanc- ing and receding glaciers. Because of its high density, the gold has separated from the country rock and by fluvial action has accumulated in local depressions. Such sites have been and may again become the loci of gold mining operations. u. Glacial lakes for power and water supplies are abun- dant in coastal Alaska. In-silting of both natural and dammed lakes is thus a problem to take in account. Many of these lakes are excellent sites for hydro-electric programs. As power requirements grow, a careful study of the glacial-lake phenomenon will become necessary in many areas of Alaska. 81 Salmon Creek Reservoir, 3 miles north of Juneau, is a dammed glacial tarn, impounded in an abandoned cirque and fed by two glacial stream. It provides a municipal water supply for Juneau. Since the Boundary Rangerof Southeastern Alaska contains many such natural basins where clear water is avail- able, the potential for development of relatively small low- cost water supply projects is also evident. The need for a practical. understanding of related glacio-hydrologic problems will have increasing importance in this area of interest. It is hoped that the present study may provide some guidelines for future glacio-hydrologic assessments. 5. Lake Atlin,65 miles north of Juneau, represents what someday may be the site of a large-scale hydro-electric ower and water pro ect. Fed by glaciers o? the Jfineau Icefier this lake lies Canada, and is the ultimate headwater of the Yukon River. It occupies a glacier-carved valley 75 miles long, varying from 2 to 5 miles in width. Once tapped it would serve as a strong incentive for joint U.S.-Canadian industrial development in this part of North America. VI. SIGNIFICANCE OF THE 1961 STUDY The investigations described in this dissertation have been conducted as part of the long-term Juneau Icefield Re- search Program under the sponsorship of the Foundation for Glacier Research. The neve, meteorologic, and glacioehydro- logic observations and measurements add to the aggregate of data which has been assembled annually on this icefield since 19h6. The present discussions have dealt only with regime aspects covering the decade 1951-61, and with special emphaskz on the 1961 records. It is hoped, however, that the new in- formation provided and the related evaluations will serve the broader purposes of the long-range program. The writer be- lieves that with respect to the study of the icefield system as a whole it has helped to clarify several previously hidden Irelationships, and also has solidified the foundation of rqfime statistics covering the last decade. This cannot help but serve as useful reference for future investigators. In addi- tion, it is hoped that this study will prove helpful in fur- thering the methodology of field measurements and interpreta- tive techniques in the glaciology of this icefield. From such sequential effort will come the eventual understanding of the true causes and manifested effects in the birth, life, and death, and indeed in the multiple re-incarnation, of this huge glacier system. From the examples which have been cited as to the prac- tical uses of glaciologic data, the value of continuing in— vestigations in glacial regions should bccfiwious. This should 82 83 be particularly so in the Juneau area, where huge and spec- tacular glaciers and snowfields lie so close to a significant center of population. The increasing potential of this type of research is germane in other sectors of Alaska too. Along this whole coast it may be expected that future activities will develop where glaciers and their summer neves can pro- vide important recreational facilities, and where impounded glacial water can be used as an unlimited natural resource for important municipal and industrial water management and hydro-electric programs. Glaciers are already being tapped for such purposes in Switzerland, Austria, and France. Glacio-hydrologic plans are underway in the south Argentine Andes and are being given serious consideration in the Cascade Mountains of Washington state. In fact even on the flanks of the Himalayas Communist China is working on the problem of glacial runoff as a source of water for irrigation projects and future hydro-power developments. Today, the world-wide recognition of the potential and practical use of glaciers for water and power supplies is strongly evident. VII. SUGGESTIONS FOR FURTHER INVESTIGATION It is stated again that because of the widely integrated nature and long-term aspect of the separate phases of the Juneau Icefield Research Program the study here presented must not be considered complete. It is but a segment of the continuing investigational program now in its 17th consecutme year. Thus it is in order to provide suggestions for further research that has been brought to light by the present treat— ment. This, of course, does not ignore the continuing need to pursue future measurements using similar and already estab- lished lines of investigation. The first suggestion is that more detailed neve studies, and particularly further geophysical, ablation and water per— colation measurements must be made on the crestal neve. Par- ticular attention should be paid to the higher Gilkey Neve because of its apparently anomalous character, and also to the highest neve of the adjoining Llewellyn Glacier on the continental side of the icefield. These studies should be much more extensive than was possible within the time-limits of the 1961 summer field season. Ideally the period of in- vestigation should be planned to encompass completely the ef- fective ablation season. This means from early June through August on the upper neve; and from mid-April through Septem- ber on the lower neve. Consideration should also be given to special observations during the winter-to-spring amelior- athm1period, particularly over the months of February through May. 8A 85 In this connection the Camp 9 or intermediate neve shouki also be fully developed as a research locale. Here, investi- gations similar to those on the crestal and lower neves smxfld be conducted. The Camp 9 sector is the link between the crestal and lower sectors. In this sector, comparative studies could permit the establishment of a long profile of geophysical and glacio—climatologic parameters for the Juneau Icefield as a whole. From the 1961 and previous saline content analyses, it would appear that here is a useful criterion for determining cyclic storm track shifts. Furthermore, the analyses should prove useful for the detection of ablation horizons and for differentiating retained segments of annual accumulation in deep firn profiles. Due to the dearth of data gathered to date, more systematic and complete surface sampling should be conducted on the key central névés, as well as on peripheral glacier neves such as the Lemon. Added to this should be complete sampling at depth across the same three main accumu- lation zones. In this way sufficient data should be obtained to make this technique useful, and to provide enough back- ground statistics to make future comparisons valid. Also, in order to make more effective the study of glacio- hydrology for possible commercial exploitation a full ablation season should be spent at selected observation sites on the Lemon Neve as well. As part of this program a first hand ex- amination of the direct effects of ablation on propagated water percolation, and of the pertinent meteorologic controls, 86 should be carried out. In this, a continuation of the hydro- graph record at the Lemon Glacier terminus will be invaluable. Here and on the 6500-foot neve of the main icefield pre- cise glacier thickness, firn-pack and deep ice structural measurements should be made, using seismic and core-drilling equipment. In otter words, surface and subsurface studies should be conducted to parallel those being carried out on the main neves of the icefield, but directed more fully to the problems of reservoir capacity and to the factors pro- ducing runoff. In this the U.S. Geological Survey should be encouraged to continue their hydrologic data collection at the Lemon Glacier site; and the U.S. Weather Bureau should be urged to establish a precipitation gauge on the Lemon Glacier Neve to permit a closer evaluation than has been pos- sible using the data obtained at the Mt. Juneau site during the summer of 1961. Although in this dissertation an attempt has been made to explain the hydrograph anomalies of the Lemon Glacier dis- charge, actual field research is required to determine whether the provisional explanations provided are fully valid, or whether the anomalies are the result of still unrecognized effects. Much more work should be carried out on mechanics of the periodic floods from ice-dammed lakes such as the Tulsequah and unnamed lakes impounded along the Gilkey Glacier in the Berners Bay Trench. This problem appears to require as muCh a geomorphic-hydrologic approach as it does the climatologic. 87 Field work should be carried out directly at the scene of these glacier bursts during the height of the ablation season. This should be done in the interest of providing effective methods of arresting these and other such floods elsewhere in Alaska, or for that matter in other parts of the world, such as the Andes or Himalayas where similar catastrophic events have resulted in much loss of life and property in recent yams. Lastly, from this present study it has become quite clear that a continuous record of temperature, precipitation, ablation, and runoff should, if at all possible, be kept over the full season of activity on all future field operations in this critical glacier region so close to Alaska's capital. To this end the present field research facilities and stations should be improved and consolidated, so that an even more complete and systematic observational program can be developed on the Juneau Icefield. In this way much more sophisticated and refined evaluations will become possible. And in this way the details of long-term climatic trends can be more adequately recognized and made more useful to the public in terms of actual forecasts of climatic events and their gla- ciologic and hydrologic results. - finis - VIII. REFERENCES CITED Crary, A. P., et a1. (1962) The United States Glaciological Researches During the International Geophysical Year, Journal of Glaciology, Vol. h, No. 31, pp. 5- 2h. Kerr, F. A. (193h) The Ice Dam and Floods of the Talsekwe, British Columbia, Geographical Review Vol. 214, pp. 6143-145. , (1936) Extraordinary Floods of Talsekwe River, Taku District, Northern B. 0., Transaction of the Royal Soc of Canada, Series 3, Vol. 30, Sect. h, pp. 133-35. Leighton, F. B. (1952) Investigations in the Taku Glacier Firn, Juneau Icefield Research Project, l9h9, J:I.R.P. Report No. 6, American Geographical Society, pp. 23-H8. Marcus, M. G. (1960) Periodic Drainage of Glacier-Dammed Tulsequah Lake, British Columbia, The Geographical Review, Vol. L, No. 1, pp. 89-106. McCall, J. E. (1952) The Internal Structure of a Cirque . 'Glacier, Journal of Glaciology, Vol. 2, No. 12. Miller, M. M. (1952a) The Application of Electro-thermic Boring Methods of Englac ial Research, Arctic Institute of North America Report No. 2, Office of Naval Research Project 86. Also published Memorandum 195R, Foundation for Glacier Research. , (1952b) Preliminary Notes Concerning Certain Glacier Structures and Glacial Lakes on the Juneau Icefield Research Project, l9h9, J.I.R.P. Report No. 6i American Geographical Society, pp. 67-80. , (1953) Chemical Analyses of Snow Samples for Chlorides, Juneau Icefield Research Project, 1951 Winter, J.I.R.P. Report No. Q; American Geographical Society, pp. 35-56. , (1955a) Glaciothermal Studies on the Taku Glacier, Southeastern Alaska, Publication n0 39 de l'Association Internationakad' H drolo ie Assemblee Generals de Rome, Tome IV, pp. 309-%7. ,11955b) A Nomenclature for Certain Englacial Structures, Acta Geograppica, Vol. 1h, pp. 291-99. , (1956) Glaciology of the Juneau Icefield, S. E. Alaska, Office of Naval Research Report on Task Order 83001 2 Eds., 800 pp. (1958) Glaciers on the Rampage, Science World, Vol. 3. pp. -7. 9 88 89 , (1959) Summary Report, Geoghysical Investigations of Project Crater (Classified, U.S. Air Force, Air Research and Development Command) Foundation for Glacier Research, Inc., 217 pp., Oct. 1959. , (1961) A Distribution of Abandoned Cirques in the Alaska-Canada Boundary Range, Geology of the Arctic, University of Toronto Press, vol II, pp. BBB-M7. , (1962a) Dynamics of Propagated Water in the Juneau Icefield Neve, Journal of Geophysics (in m.s.), abstract presented at American Geophysical Union, h3rd Annual Meeting. , (1962b) Glacio-hydrological Regime of the Lemon Glacier Alaska, American Journal of Science (in m.s.). Twenhofel, W. S. (1952) Recent Shore-line Changes Along the Pacific Coast of Alaska, American Journal of Sciencel Vol 250, pp. 523-178. Victor, P. E. (1952) Memorandum on the Greenland Ice Cap In vestigations Of Expeditions Polaires Francaises in l9h8- 51. Notes with Mr. Victor, and review of his published reports. Prepared for use of Juneau Icefield Research Program, Field Memorandum No. 2, Foundation for Glacier Research. Wallén, C. C. (19h8) Glacio-Meteorological Investigations on the Karsa Glacier in Swedish Lapland, Geografiska Annala, Arg. 30, tart. 3-h. Climatological Data, Alaska (19h0-61) U.S. Dept. of Commerce, U.S. Weather Bureau, Vol. 26, No. l3-—-VdL A7, No. 10. Lemon Creek Discharge Data (1951—1958) Quantity and Quality of Surface Waters of Alaska, U. S. Geol. Survey Water Supply ngers lh66, lh86, 1500, 1570. Lemon Creek Discharge Data (1959-1961) U. S. Geol. Surve , ¥ater Resources Division Office, Juneau, Alaska, 0 ice 119 e IX . ILLUSTRATIONS 133‘30' 134'}o° "iuosx MP I, GLACIOLOGICAL \ .J‘ ‘ .5 w I ossznmonv e omen PERTINENT must: cam ““42, OMTJUNEAU Avie RESEARCH SITES an. ‘ao JUN EAU _‘ 2 ”PM Jule of M ”a ; more i n: of I960 .339: 133‘30' LALA A cal 96!. nd Cempwldev.4,ooo¢r.) Atwéflfi. 5,000 He 'cinir «Meet ’0 m1 OM Juneau Icefield end w P headquarters 01’ Camp 5 (elev. pail-M lecier research star r Institute sum. me .3. and Sum Fig.1 91 . /eeec e 7.. z / The. .@ WWW/m ,/ .. ..M ii. MM/ xx c .% Wax/Wu fl/Vyflw P (/ . I‘ as I ell s e .£. .. Ll... 64... 54.... a... / SYSTEM snowme RESEARCH sures, I961. 92 ' FIGZ SKETCH MAP OF TAKU GLACIER Main Drill 20A. S-Vay switch “ s >' 35 g i‘.‘ O c: as Q ‘3 S ra—lS'QD. -’l, , 'lPs..—“Fm "‘7 Galvanized I Pipe ‘ Machined | Brass Tip I HEATING CABLE LINE [ I20v. LINE 5;..-J I *‘a 1 A/fil LINE KEXTRAETOR HEATING ELEMENT I. fleet/h] cable for fay/n] lo card on 16 ”centers. 2. 70 but cable, I 4/»: swift/red from flea/Pr lo beef/'0] cob/e My: awe/my Me deaf define/I flee/tr 9 0'17” 01}? 3. ”/2 wire used to nearer to ova/2d line drop. FIG. 3 ELECTRO-THERMIC GLACIER DRILL 2000 we" element; I20 voll’ wiring detail as used al’ Sil’e 8A. Upper Taku Glacier, elevel'Ion l”00”., Augusr - September, I961. FEE! DE'TII mum m: “I! (mm nu ma) Isnnmm («I II I”! ”Cf-flu .g. .u ..5 .1, -I.I a "II “'3'" (”I“) "3'!”‘P’."P_PILIIIIIIII"'"P‘!" l ,,,,,,, Iw umIIIII sum: 4 I ‘ - ’ I» E ._ ._-_. _. _. L._...-’.__._.—-_:-I..‘O-—-— -ti.’.‘_._ -1— 1" :/ nee-AL ensues «me In ,,,,,, In: at were men seat 1% /” ‘ / 5-- :=—--._ _____________ u. 5.. 50 ~ I I l l 7. I I l 00‘ I I I ,4 e . e um mun sue-smut : scrum: I’M Hummus moms: mum menus I _ . ‘4 ? ® Ingram "mums em I a» u an. we sumo-mm: mums Rm III ‘ I —am IIRILL cut - . - — u - my ”Ir-3m. 'eI " ‘ ----- u net-not: or um mu. ---- cw u- Imam-st". 'sI ' um I”? (mu cum) 2.5 xv um mu ”2 (mo men) I I —-~---«- w» ee-suv sew-ween . I m, ‘ —u ust-um or um sun-II. mu m IIIIIIIII wan) ‘ l I "“- '5 ""' ”V" — aw dl-ELEV. sIoo-sm'w I g: acumen u" mm; mm 329 (mm It!!!) I : muse am am A! “Helm - - ‘0‘" "I" “W 5500‘ n " mj ‘ ..D "o u "m U.“ 332 (“I9 “I“ ‘ I a..._omu Al’ IIIIIIII um III I -.- Revs-sun I»: ma III I m. I am assume some. I I I I '9" g I I I ' I In 1 i I I T 1 FIG. 4 5 3 I 5 menu am am (Isms m III-m) III I951 Int-m IIIIIIII ~03 -II.7 4.5 4.3 I 4| M'AIATIVE PROFILES 0F TIIIIML “IE-RATE, llflAClAL mmumt AID DEISIW II TIIE cmm IItvI, IIIIIII-IIEIIIILIVII sum: svsmI. JIIIIIAII ICEFIILDJIASKA (upscale, M at. d Wanna) 9A FIGJ S.I.P.R.E. 5 INCH O.D. HAND AUGER. . I. FICA) l‘IIEI’IST‘IJNC ERIN: , SELECTOR S (I I‘C ‘ AND T:I..R'-'ISTOR GLACI )- T.I_.R.'IAL CABLIS UScJ )ls' TIII JUNE. U ICL'FI .LL ) 51;.5 :ARCH PR )LJLAH, 196U Hi) 1’01. 95. 20.b_moa ux'>: r V V V r V V j V r I V V V V V V V V V V V —V 1 V V V V V V V j MEAN VALUES, STAKES A -I VVVVVVVVVVVV ' V V V r V I V V V V 0 ... aununflfll23456189wnnnu5wnmnmnruunu JULY, I961 AUGUST 1961 98 ’3; ' 9 scmmm IssI noucm suunce L IIsw snow I 1 _!IL2:_"5_.___. L ow snow I 0“" 4 ! um HMR ' I96! AILATIOI sum: 5‘51"?— 2 F II!!! 0.1 25 $1 I . 4T —— —| W'” ===-. I : 00.0mm 6 _-- 00.9513 I 29mm: 8‘ l — 88 —__.‘_——'_.I 31.1 "M um «I I I I FIG. IO I24 fil’: WALL PROFILE, CAMP 8A TEST PIT, l96| I SHOWING FIR“ STMTIGRAPHY, PERCOLATION I PAN POSITIONS,AND SAUIE SAMPLE LOCATIONS , (JAIN: 5.4mm: lb 09.9mm 4T» $.. ”MIMI/ow PM I - - ' T . .. o/Amvzr/c It! ”wen/kt: l6-I I ml ..u I ""IW “mm sun'—nct':_otnu non 20] scum mu. WEST WALL 99 (II FEET) DEPTH FIG. II STRATIGRAPIIY FROM SIPRE-DRILL CORES AT CAMPS 8All9AJ96I CAMP u - ELEV. 5950' a'lmrmsea I96I sunmc to r *Jy '. m ' ' ' ' ' ' ' ' ’ ' ' "I '.'.78-'_~——=——am'.'.‘ ”.Z'.‘ ' Z " Z I 20 a '5' .S' \ 30 -I . t 3 “A! I“ I .5' w d .5' LL. so ‘ DUI.“ GI. ICE 3-5' ' —I.L. a? so I A... I'Mflfll-IOM 204’! U... If! 579.474 IIC/P/flf C... 20" MPH-flail 1M! 2212': bow-boar 100 CAMP 09A - ELEV.6500' 8"“ SEPTEMBER I96| SURFACE Ll. '- 1.5. 1121...: 1212122 - 3319?- ' ' 7 1'. 1...... 11:: STRATICULAVED - M I 3-5 I? 24' I“ m D ~ I“ - ‘ * — -- --'--- 1‘6“}.-- - E gnu m I“ ‘ V!" m“ mu“ _ fl 1qu or mv Icé mm -— (“WW _. ~ :I F N??? > ) «I— .- —--I' ("Diff/{5404! 2M! (MRSIZY CRVJfAll/A’l . ICI 570471 Mf/P/[A’f .. ICI 57.04711,” (M23127 flrflMl/K . DIISI WATER-It“! .. 0575'! WATIRJCI All [£03159 10’ ”0 W475! letr: . an: Ice; slut/u: y out/u lté' 0’ [If]!!! $10!. All [0018! #0 WA)?! PMIIJ. II FEET DEPTH FIG. I2 STRATIGRAPI-IY 0F CREVASSE WALLUPPER TAKU GLACIER SITE an, ELEV. 5700', snow or am 8,1961. I3 SE'TEMBER I961 FIDUCIAL SURFACE o 1961 A.S. I LEI- NOTATIONS . l l '0 " ' I I I7 6" . l | 20 I960 AELAIION SURFACE l I l D I959 AS. 4 6 , I958 A.S. 2'3“ 4 1.5., M" _— 5'15. --‘.--~.—'3_-—'- A—w— ' . ' “I - 'I.S. Inf. 3" I957A.s. 1...,“ 45 ( )I «I I 6' I956 A.S. I ‘° ‘ 1955 I 4' d— “u.-- _ “-—"L F6..- 4.. 1.5. (Int) ’0 db- - -— -—n. -..- -—- --—- -—--—- C‘..+ 6' — 2"I.s.(1nr.) 1953 A.s. I ‘ V.V.D.L. I 6' I952 M. I ‘0 ., —‘[ V. D. L. ' 6'6“ ., IQSI AS. ' r— v. D.L. I 10 ~ . 8‘ I950 A.S. I ?) I I K j RELIcI LEVEL or IMPOUNDED ”:0 I so .. I.S.(Inr.) 2 IEE SIRAIUM,(1nr¢rmIIIenr) 1.8. . ICE STRATUM 0.1.. = DIRTY LAYER - V.D.L. . VERV DIRTY LAYER V.V.D.L. = VERV VERV DIRIV LAYER ’0 ‘ APPARENT Barron or FISSURE A's' ' "w“ Ammo" wan“ I---- 101 1.2 - CAMP I0 8 60 6| “cm / IIEVE w. or 5mm PK. . EILKEV "0 NEVE 9/6I Em 0.8 - i3 '2' 8/60 LEA Iti‘glm‘ , 0.9 SEUOR E. 0.5 " ‘2? a. '0 °' 20 ' f (2.20 as. 0.4 - ' IIEVE < + INTERMEDIATE (r ; NEVE IOWE}? 0-2 ' NEVE D V 1 I I I I 3500 4000 4500 5000 5500 6000 6500 VEVE’ ELEVArIoII III FEET FIG. I; DISTRIBUTION OF NaCl CONTENT AT SURFACE OVER JUNEAU ICEFIEIDJIASKA (sem'I-Iog plot) DEPTH IN FEET ALILL IOO~ :00 I 600 4 *— SURFACE, MID-WINTER ‘— 2/I4 - 2/Ia, I95I Ioé—sumcs, LATE SPRING IL—‘ 6/II/5l I (SHALLOW SAMPLES) ‘ ~ ‘ ~ ~ ‘- § ‘ FIG. I4 SODIUM CHLORIDE CONTENT OF SNOW. FIRN, AND DEEP ICE SAMPLES AT CAMP IOB. 1000 I ‘ .p.‘ \h 0“ DEPTH (III FT.) * R as 1 O 1 IO" I2‘ 101. 1622 30mm CHLORIDE CONT’EN’T IN FIRN or CRESTAL NEVE —— 9/I2/6I - CAMP 8A -5950‘ ......... 9/6 - 9/8/6I - CAMP 8A - 5950‘ ---- 9/8/6I - CAMP I9A ~6500' w7771'vvvv'vvvavvvv‘rvrrTw VVVVV 'VV'VIYVVV‘rV'VVIVT'V'VVVV'Y—VYTIVVVV 60 M c: I I M o '0 AAIA‘A‘“AA‘1A‘AA1A‘A"A.JH‘AlAAA‘lAA-AlA‘AJJAl“lL“Al‘LAAl.A“ I0 I520253OSIOOSIOI52025305 APRIL SEPTEMBER OCT n“ , I‘d. - It": 1 1"! u 'N‘1 ‘ “l.‘l ““ fl—FpIrp-nurth-npp»~..LILIILIbIbIhIF|ILIF-~LILIIbLLI~LIhILIrLILIbILLLRLL~LthILLIN 3.2 .53 .222: 2:28 92 353. is: 8.8: 3.323 32.39 8.“: a3: «a 53 .2322. .5 3333 329355. E. 2:28: .2 ES 3 29:3: 2 maaéxz: 31:3: 25: h. .9: «.23 5.292: .2 2.8 .555 253. .5 3&3 33:2...) .2 .52: 3.3.: .._< 52:: +833 33:34 @4wa .0 _ AI 0 .. J a h T .... 1 m o. I 3238 ....... L o. n. I chug“... amen”. I a. 3 I (4. L on Q. I I 3 o I x I cm K! [.II I ll Ill] lllll .- [I IJI INN 1 I; x ..~ m mm 0‘ I ’x «as ...m l a. a. I all\\ ..~ I. “V on I m o I on a I So. «as. S .2: 3o. .3. R J bbrn be-bhbpppppbbb-Nb—pb—pb—b-bepbbbLbrbbLh—hbbbp—-—+~F 106 (0% so SJIIJIU) nolgumm "_ v- 22” 3 .3; a; - Eda. 3 -‘->' r. 3; “2.3" a p "’ Q2 3‘... :1 d a g g at: =3 1 5" a: '- -* 33* " c < 8 Q :0. — I: 3 fi (o‘n so mm) nougumm JUNE AAV APR". .- O lul‘ V V" N '- O (01" so SJHJII) uauvumm (o‘n 10 5mm) noumanm 107 (a‘n 10 5mm) uouvumm fi M «a summmo um so m (091 10 53mm) uoummm 108 ' 25 AUGUST SivTEAIER F|6.|9 DAILY PRECIPITATION,MT. JUNEAU SITE. ELEV-3600' JULY PERIOD: 1JUlY - 27 SEPTEMBER. 1961 35825 .34. .3: I333 xuzz< .: a: -5022 3:23, .I I I I .§ .3: I ES 2322. .......... $2IR$ .‘-‘ E 3‘: a: '3 >9nv é 3 2 3 NM 5': 9.. INFIF WW :3 “Hg 3 e .. WW --'* -~* ‘ - * - -——1’330 93 931 I >A0N INTI .130 —— —* ,7, 7 him was lHum ~9nv T130 , 1M > dIS ~NnI‘ {SM 4W , Tflf '- *UdV «M ‘61 mm PAVW ‘— I83! 3?, *UdV Iuvr , 9; mm I———--- —— -- 3m ‘ I931 PMJN +NVI‘ - 130 — ~ , ——~»330 dJS *AON >9nv >130 r 101‘ ~d35 INflI‘ E Iva ,9: 4m NI am mm m m m: 9mm mafia ’53: ....... In" 330 MON - DO -d]S Ionv Ian ’an PMW -lIdV MM Liii ~NVI‘ ~Jld PAON ~130 >d3$ I9nv ~Inr .unr >AW >ddV -IIVW ~——~ L831 *NVI‘ 6—— ~-——8 --~ -—-—; ~- — —-—~ --—~—~—;_ 130 L» ~--— é ; 330 Md 50I'W35 mw A‘IHINOW ($13) asaanSIo 9‘ Jold5°|"W3$ “Imw Immow (311) SSUVHJSIG a 3 > £9 OW. am: are 5. fit «3. the RI: a: P D at 3. tuba—ommtxu .. . . ..... d dw02u4 39 39 a: “a. Re a: a: :2 $9 an: O p p b p p P a»... p 8“ 3.232.; m ......... A .. (again IIIII onIIIIIo ...... ........ oI I m M N. antiqz xx m w w . 2:. m .1. \\ .8 .8 .H w w x m m r m IIIqx . n O ..a \\ .3 IN. V: o \O\\ M raem H \ o ..l o u xx m. A m w. OI n .., .9 m \w m m on .9 . . rug 8 w V w Q1 \ IQQN Bx .\ m 5.2: .323“: 2323. 2 32.33 3»; @263 H.533 x33 2:23 t. .28 3:: “82:38 23: ._<=22< $252.2 .23 £=¢<§<€ a d: (:13) 393mm Ammow uvaw wnmwi 11h 3351329. .523. .axdsa;a=aa.sma.szu.nsduzc.:a 5.55“ a - :5 m. 3.5. g. "a: .2333 it :3 3.315562...» 5...... 5.3 .35.. 8a.... 52 3.3:: R t 2 c u+lll h L L L P F hm=w=< t D! >J=H aammma P b a u‘ R *C *8 w w‘ m m m 9... a v S J H w v .0 OJ 99.. 3 xl/ J _ J _ S _ _ _ _ 25.? “2:5 m. >2 kn .__:< m. +9 (513)395vnjsm 115 of‘ ‘ ..7 '1‘ .opdm wcawsuw xooho :oqu on» cam .ndmam ommaaahm and no hhuvczom on» .hoaouau noqu on» mcflaona Aoom.mouav uoamauucasa m-m can H-m «guaa< .saonsu pm .mfim ! 116 X. APPENDED DATA Date 8/29/61 8/30/61 Tune 1815 1845 1915 1945 2015 2045 2115 2145 2215 2245 2315 2345 0015 0045 0115 0145 0215 0245 0315 0345 0415 0445 0515 0545 0615 0645 0715 0745 0815 0845 0915 0945 1015 1045 1115 1145 1245 1315 APPENDIX 1 Camp 8A - Thermal Bore Drilling Rate Readings, 1961 elev. 5950 feet Advance Ft. In. 05 10 07 06 08 l l 02 1 l 04 00 05 08 05 01 08 0'7 00 09 02 08 08 02 08 08 0'7 09 11 00 01 08 03 10 08 00 09 00 03 r—‘I—‘ONHt—‘HHHNHl—‘HONNHNNHWONNNNONOl—‘Nt—‘t—‘l—‘HHH In. Remarks 00 Starting point in bottom 05 of hand auger hole. 07 02 These two readings obscured 02 by rope being caught. 11 Ol 09 05 07 03 11 O6 03 02 02 03 11 02 00 O8 08 05 ll 02 119 Camp 8A - Thermal Bore DrillingRate Readings) 1961 (cont.) Advance Degth Date Time Ft. In. Ft. In. Remarks 8/30/ 61 Brought forward 87 02 1345 0 08 87 10 1415 1 01 88 11 1445 0 06 89 05 1515 0 10 90 03 1545 0 07 90 10 1615 l 03 92 01 1645 1 07 93 08 1715 1 05 95 01 1745 0 06 95 07 1815 0 05 96 00 1845 0 03 96 03 1915 0 07 96 10 1945 0 10 97 08 2015 0 06 98 02 2045 0 07 98 09 2115 0 07 99 04 2145 0 07 99 11 Generator left running, no 2215 0 07 100 06 reading taken, for a total 2245 0 07 101 01 advance of 4 ft. 2315 0 07 101 08 2345 0 06 102 02 8/31/ 60 0015 0 00 102 02 Generator not running 0045 0 00 102 02 during this period. 0115 0 08 102 10 0145 0 04 103 02 0215 0 07 103 09 0245 0 04 104 01 0315 0 04 104 05 0345 0 06 104 11 0415 0 05 105 04 0445 0 01 105 05 0515 0 05 105 10 0545 0 05 106 03 0615 0 10 107 01 0645 0 04 107 05 0715 0 00 107 05 0745 0 06 107 11 0815 0 01 108 00 0845 0 06 108 06 0915 0 01 108 07 0945 0 04 108 11 1015 0 03 109 02 Date 8/31/60 9/1/61 'Thne .Advance In E1. . Brought forward 1045 1115 1145 1215 1245 1315 1345 1415 1445 1515 1545 1615 1645 1715 1745 1815 1845 1915 1945 2015 2045 2115 2145 2215 2245 2315 2345 0015 0045 0115 0145 0215 0245 0315 0345 0415 0445 0515 0545 0615 0645 OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO 04 04 03 06 03 04 04 04 03 04 04 04 06 03 04 04 06 04 03 03 03 03 03 03 02 00 00 03 03 01 01 03 06 02 03 02 06 03 02 05 04 12 0 Camp 8A - Thermal Bore Drilling_Rate Readings. 1961 (cont.) Depth 109 109 109 110 110 110 111 111 111 112 112 112 113 113 113 114 114 115 115 115 115 116 116 116 116 117 117 117 117 117 117 117 117 118 118 118 119 119 119 119 120 120 __..__In_: We 02 06 10 01 07 10 02 06 10 01 05 09 01 07 10 02 06 00 04 07 10 01 Generator left running 04 for total advance 07 of 1‘ 8”. 10 00 00 Generator not running 00 during this period. 03 06 07 08 11 05 07 10 00 06 09 ll 04 08 Date 9/1/61 9/2/61 'Thne .Advance D1 PW. . LBroughtforward 0715 0745 0815 0845 0915 0945 1015 1045 1115 1145 1215 1245 1315 1345 1415 1445 1515 1545 1615 1645 1715 1745 1815 1845 1915 1945 2015 2045 2115 2145 2215 2245 2315 2345 0015 0045 0115 0145 0215 0245 0315 CDC)OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO 04 04 01 03 04 01 02 04 04 02 02 02 05 03 03 04 03 01 04 03 04 02 02 04 05 04 05 04 04 04 00 00 00 00 03 03 02 02 02 03 03 121 Camp 8A - Thermal Bpre Drilling Rate Beadings, 1961 (cont.) Depth 120 121 121 121 121 122 122 122 122 122 123 123 123 123 124 124 124 124 125 125 125 125 126 126 126 127 127 127 128 128 128 128 128 128 128 129 129 129 129 129 130 130 hi PT. . 08 00 04 05 08 00 01 03 07 11 01 03 05 10 01 04 08 11 00 04 07 11 01 03 Remarks _ 07 00 04 09 01 05 09 Generator left running for total advance of 2' 6". 09 09 09 09 Generator not running during this period. 00 03 05 07 09 00 03 122 Camp 8A - Thermal Bore Drillirg Rate Readings, 1961 (cont.) Advance Depth Date Time _1_7‘_t_._ _Ir_1_:_ fl; LIL Remarks 9/2/61 jBroughtforward 130 03 0345 0 02 130 05 0415 0 03 130 08 0445 0 04 131 00 0515 0 02 131 02 0545 0 06 131 08 0615 0 00 131 08 0645 0 02 131 10 0715 0 03 132 01 0745 0 02 132 03 0815 0 02 132 05 0845 0 02 132 07 0915 0 02 132 09 0945 0 04 133 01 1015 0 02 133 03 1045 0 05 133 08 1115 0 02 133 10 1145 0 04 134 02 1215 0 00 134 02 1245 0 03 134 05 1315 0 06 134 11 1345 0 03 135 02 1415 0 02 135 04 1445 0 02 135 06 1515 0 01 135 07 1545 0 02 135 09 1615 0 02 135 11 1645 0 02 136 01 1715 0 02 136 03 1745 0 04 136 07 1815 0 03 136 10 1845 0 03 137 01 1915 0 03 137 04 1945 0 03 137 07 2015 0 05 138 00 2045 0 05 138 05 2115 0 05 138 10 Generator left running 2145 0 05 139 03 for total advance of 2215 0 05 139 08 2'11'K 2245 0 05 140 01 2315 0 05 140 06 123 Cam_p 8A - Thermal Bore Drilling Rate ReadingsL 1961 (cont.) Date 9/2/61 9/3/61 9/4/61 Time Advance £11 In; Brought forward 2345 0015 0745 0815 0845 0915 0945 1015 1045 1115 1145 1215 1245 1315 1345 1415 1445 1515 1545 1615 1645 1715 1745 1815 1845 1915 1945 2015 2045 2115 2145 2215 2245 2315 2345 0015 0045 0115 0145 CO OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOI 00 00 00 06 04 02 02 02 02 02 02 02 03 03 01 04 06 05 04 02 05 04 01 01 02 02 03 02 03 02 02 00 00 00 04 02 02 03 04 Depth _Jg 140 140 140 140 141 141 141 141 141 142 142 142 142 142 143 143 143 143 144 144 144 145 145 145 145 145 146 146 146 146 146 147 147 147 147 147 147 147 148 148 In; 06 06 06 06 Remarks Generator not running. No advance, rope frozen in hole. 00 04 06 08 10 00 02 04 06 09 00 01 05 11 04 08 10 03 07 08 09 w 11 01 04 06 09 11 01 Generator left running for total advance of 1‘ 4". w 01 01 Generator not running during this period. 01 05 07 09 00 04 1211 Camp 8A — Thermal Bore Drilling Rate Readings, 1961 (cont.) Advance Depth Date Time Ft. In. Ft. In. Remarks 9/4/61 Brought forward 148 04 0215 0 04 148 08 0245 0 04 149 00 0315 0 01 149 01 0345 0 01 149 02 0415 0 00 149 02 0445 0 02 149 04 0515 0 02 149 06 0545 0 02 149 08 0615 0 02 149 10 0645 0 02 150 00 0715 0 02 150 02 0745 0 02 150 04 0815 0 01 150 05 0845 0 02 150 07 0915 0 01 150 08 0945 0 02 150 10 1015 0 02 151 00 1045 0 02 151 02 1115 - -- --- -- ROpe frozen in hole; drilling completed. 00.0: 0000 00.0 n 0000 00.0: 0000 00.0 n 0000 00.0: 0000 00.0 u 0000 00.0: 0000 00.0 a 0000 00.0: 0000 00.0 n 0000 00.0: 0000 00.0 n 0000 00.0: 0000 00.0 I 0000 00.0: 0000 00.0 n 0000 00.0: 0000 00.0 I 0000 00.0: 0000 00.0 a 0000 00 .0: 0000 00 .0 .. 0000 00 .0: 0000 00 .0 I 0000 00.0: 0000 00.0 n 0000 00.0: 0000 00.0 a 0000 00.0: 0000 00.0 s 0000 00.0: 0000 00.0 n 0000 00.0: 0000 00.0 + 0000 00.N+ 0000 00.00+ 0000 Am. 00. .Mw mm .0000 0000 .0000 0000 00\0\0 mmuauuvw OouB 00.0- 0000 00.0 0000 00.0- 0000 00.0 0000 00.0. 0000 00.0 0000 00.0- 0000 00.0_ 0000 00.0- 0000 00.0 0000 00.0- 0000 00.0 0000 00.0- 0000 00.0 0000 00.0- 0000 00.0 0000 00.0- 0000 00.0 0000 00.0- 0000 00.0 0000 00.0- 0000 00.0 0000 00.0- 0000 00.0 0000 00.0- 0000 00.0 0000 00.0- 0000 00.0 0000 00.0- 0000 00.0 0000 00.0- 0000 00.0 0000 00.0- 0000 00.0 0000 00.0- 0000 00.0 0000 00. mm 0. 00 .000 0000 .000 0000 00\0\0 000 0000.0 .000: 0.000 00 0005 * 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0. 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0. 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00.0- 0000 00 .0- 0000 00 0+ 0000 .0 00 .0 00 .20 0000 .000 0000 00\0\0 0000 0000 SEE m0omnm0om 000.0000 1 3500000000002 0000000000000 .. <0 9800 00QQZHQQ< 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 IIMMMII 000009. meéfib "MHQEM *- r—INC‘OWLOQOD-(DOD 00 00 00 00 00 00 00 00 00 125 '126 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 - 0000 00.0 0000 00.0 + 0000 00.0 0000 00.00+ 00000 00. 00 .00 00. .000 0000 .000 0000 00\0000 00.0 - 0000 00.0 - 0000 00.0.- 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 n 0000 00.0 - 0000 00.0 . 0000 00.0 - 0000 00.0 I 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 - 0000 00.0 + 0000 00 .0 + 0000 00.00+ 0000 00.00+ 0000 um 00 .0 .m .000 0000 .000 0000 00\00\0 .0090 0.000 00 00.0. * 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00.0: 0000 00 .0... 0000 00 .0: 0000 00.0: 0000 00.Q+ 0000 00.0: 0000 00.0+ 0000 00 mm .H 00 .000H0000 .000 0000 00\0\0 0.00003 00000100000 0oomu000 u 00000800500002 00000000000000 u <0 0000000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 IImMMII 000090 mgafib MB00m Do u .0. 00.000 00000000::x.0r.r 000m:0.00m 0.000000 : 00.000000000000002 0000000000000. : 0000 00000.00 0 ”00000ng00000 00.0: 00.0: 00.0+ 0500 0000 0050 I0. .00000050 808% .000: 00 0000000 00 0:0 0.0032300 00030000 08000000 000000000 0000.30 * No .0. 0m .o+ 9. 0+ H. 0500 *0000 *0000 .mp£_0000 00\00\0 mcHnonuM0 Uouu.H S .o- Nam 00 .o+ 3% mo .o+ 3% mo .o+ $.00“ 00 .o+ 30m S .9. Son HI Im. H: .m .2: 8% .20 80.0 80003 mmm 038 00.0 8% 5000 0000 0000 IIJmmW. AC00SH m0éfib HE®._H.r_:._m 0quZMQQ< 0000000000 89000 : 0020800500002 0000080008 : 000 0000000 131 APPENDIX 6 Cami) 8X - Thermistor Measurements* - 58-Foot Bore-Hole T = °C Elev. 6500 feet Cable 329 R = ohms DATE 9/2'7A58 TIlVLE 1500 hrs. Therm. No Depth f: l 5 1' 2964 +1. 11 6 4' 3411 -1. 01 ’7 8' 3285 -O. 87 8 12' 3086 +0. 04 9 14' 3244 +0. 02 10 16‘ 3271 O. OO * Site (bore-hole ID in ice lOOO' northwest of Camp 8 on ice shoulder; cable jammed in spirally. Degth is below 1958 ablation surface upon which, on 9/27/ 58, lies 1. 5' of new snow. 132 Ho .0+ No .o+ mo .o+ Ho .0: mo .o+ Ho .0+ 00 .o No .o+ Ho .0: Ho .0: .H. mwmm mwmm vmom avam mmmm omam onm mmam mmwm mmmm ml .mp: 002 @3me a 603.25 283030 0000 9500 .0 3 800.30 38.0. 02000 ”302:0 83300 0000 328 3 £me .00\00\0 0o .20 0000 a .0 00.832 20.8 1.... so :93 coma 00 00:00.9: 0500 303.0% m @800 Mo No.o+ wmmm No.o+ mmmm No.o+ wwmm No.o+ mwmm ©0.0+ mwom mo.o+ mwom Ho.o+ mmfim No.o+ vmam mo.o+ mmmm mo.o+ mmmm Ho.o+ mmflm Ho.o+ mmHm Ho.o+ momm Ho.o+ womm Ho.o+ wmfim No.o+ mmflm 00.0 wwwm Ho.o+ mwvm 00.0 vmmm mo.o+ Hmmm H1 mm .H NH 6.3 88 AWE coma mm\©NVm dezonuvm Do as Kb 00 .0 00mm .3. mo .o+ mvmm Em no .o+ mmom .mm 00 .0 0.03m Em Hod: owmm .mm mo .o+ wmam .5” oo .o Oamm .2 Ho .0+ «imam .3 No .0: 05%. R. OH .0: 00mm $.30me H. m .mp: 002 wmvmmv m mmm @300 .00\00\0 5.80 .0000 a 22-220 0:0 1. $3 0006 53m *ofiomumpom Schuom u mEmEmQSmmg/H 0003:2039 u Wm @800 N. NHQZMQQMN 00 .0 0000 00 .0 0000 .00 00 000+ 0000 00+ 0000 .00 0 000+ 0000 000+ 0000 .00 0 00.0 030 00.0- 030 .00 s 00.0+ 0000 00+ 0000 .00 0 00+ 0000 00.0- 0.30 .S 0 3 00.0- 0000 00.0.. $0 .00. 0 B 80+ 0000 00.0- 0000 .0 0 0.0.0+ 0000 00.0- 0000 .0 0 00 .0- 0000 00 .0- 0000 .0 H ...W M: 40. [ml £000 .02 .ahmflrfi .20 0000 0.3 005 @200 00000 meg APPENDIX 8 Camp 8A - Daily Melt-Water Percolation RecordL 1961 Elev. 5950 feet (Measured in ml. ) Pan A Pan B Pan C Pan D Depth* 5 inches 28 inches 58 inches 88 inches Date 8/25/61 Pans A, B, and C Installed 26 0 0 0 27 32 0 0 28 34 0 0 29 14 4 0 Pan D Installed 30 0 0 0 0 31 0 0 0 0 9/1/61 14 O 0 0 2 15 3 0 0 3 10 0 0 O 4 7 0 0 0 5 4 0 0 0 6 No Record '7 No Record 8 1 3 2 1 9 1 12 4 11 10 125 1 3 1 11 1256 8 1 0 12 1175 6 5 5 13 1074 4 0 0 Date Time - 9/4/61 0900 0 0 0 0 1000 0 0 0 0 1100 0 0 0 0 1200 0 0 0 0 1300 0 0 0 0 1400 7 0 0 0 1500 0 0 0 0 1600 0 0 O 0 1700 0 0 0 0 * Depth, below 1961 ablation surface. 131+ APPENDIX 9 Camp 8A - Ablation Measurements1 1961 Elev. 5950 feet Date 8/23/61 25 26 9/10/61 11 12 13 (in inches of snow or firn) Stake A B C Installed (late-summer firn) 3. 9 3. 6 4. 0 Snow 135 APPENDIX 10 Camp 10 - Ablation Measurements, 1961 Elev. 3650 feet (in inches of firn) Stake H_ G_ F_ E_ D_ c_ B_ A_ Date 8815889834399 140 8645 4 L2.3.LLL0.LLLL0.0. L0..I._ HLLL 6. 4085008839538 033 1350 0 L2.LL2.2.0.LLLLLO. LO.1. B.0.L2. 6. 8304980896508 933 4019 6 0.2.2LLLLLLLLL0. 0.0.L 3.LLL 7. 41 1361044433109 939 4400 5 LZZLZLLLLLLLO. 0.0.0. M.0.L1. 7. 3636677708809 950 5536 0 1.1.2.L1.L1.LL1.1.L0. .0.0.L . .6.0.1.1. .7. . n n n1 n S e e e k5664858464109fl446nka $8835w6 mLLLLLLQZLLLLQt 1.0.0....» ..LnO.O.1.L..Lr/. S S S 81 S LL LL t LL 08685491415168 m840 %6 @1891 w94 n1111111111100m001mMm8102m6L m r r r 6.605099414549 u159m0w8431qu080 112121011111031003333111371 1a. elel e D. m m m m m8.9.15.48.3.0.6.9.3.0.0.08.9.9.0904205038 EL02.LLLLQLLLLLNLQONmleLLN90 )) )) mm mm. 0e 0e 1 1 mV mV 3 6 4 m w (re. (W 1.. 4 9... 4567890112345567789457890156 22222233/ 111112222 w 8 136 APPENDIX 11 Camp 9 - Ablation Measurements. 1961 Elev. 4600 feet (in inches of firn) Stake PALE A 13.. _C_ 2. 13.. I". 9; 11. 8/17/61 Emplacement 8/27 11.4 9.9 10.0 10.9 10.3 9.1 7.9 10.9 137 APPENDIX 12 15-Year Firn-Pack Accumulation Statistics for the Crestal Neye’, Juneau Icefield Vicinity of Research Sites 8A (59 50 feet), 8B (5900 feet), 8D (5700 feet), and 8E (5600 feet) for 1946-61 Ann. Precip. Total Mean Mean (Sept. -Aug.) Annual Increment Bulk Water Juneau Airport Budget of Positive Firn Density Equiv. Station Year Accumulation (feet) (gm/cc) (inches) (inches of water) 1961 Data 1961 1961 Data 8A Data 8A 1960-61 17. 5 0. 56 118 71 1960 Data 1961 Data 1961 Data 19 53-60: 8E 8D 8D 19 59-60 5. O 4. 5 0. 55* 30 52 19 58-59 2. 0 2. 7 0. 60* 19 58 19 57-58 6. 0 5. 3 0. 60* 38 47 19 56-57 6. 0 6. 0 0. 62* 45 50 19 55-56 2. 0 4. 0 0. 65* 31 54 1954-55 3. 0 5. 5 0. 80* 53 53 19 53-54 3. 0 6. 0 0. 85* 61 45 1953 Data 1961 Data 19 53 1953 Data 1946-53: 8B 8D Data 8B 1952-53 15. 0 6. 0 0. 61 100 62 1951-52 16. 0 6. 5 0. 55 106 46 19 50-51 13. 5 8. 0 0. 60 97 39 1949-50 17. 0 - 0. 61 124 51 1948-49 18. 0 - 0. 65 140 70 1947-48 11. 0 - 0. 80 106 49 1946-47 7. 0 - 0. 88 74 61 * Estimated values based on extrapolated curve similar to that of 1946-53. These figures are to be subjected to refinement during the 1962 summer season. Statistics previous to 1961 based on field data from M. M. Miller. 138 APPENDIX 13 Annual Primary Stratificatign on the Crestal Ne’ve/as Measured in 1960-61 Strat. Year 1960-61 1959-60 1958-59 1957-58 1956-57 1955-56 1954-55 1953-54 1952-53 1951-52 1950-51 1949-50 1948-49 1947-48 1946-47 1945-46 1944-45 1943-44 * Each site is on a relatively level neve]. Site 8X* 6500 Feet 8112fi0 CfiOCDOx'IOOCJOOOt—L J. 00 OOCD CO .8 Site 8C* 5850 Feet 8113160 1 . 9an 0000'! ice stratum 139 IO- Strat. Thickness (in feet of firn) Site E* Site 8D* 5600 Feet 5700 Feet 8113160 9113161 - 17. 5 5.0 4. 5 2.0 2. '7 6.0 5. 3 6.0 6.0 2.0 4.0 3.0 _J;;5.5 3.0 6.0 3. 5 3.41216. 0 3.0 G,"i,6. 5 4.0 "“8.0 ? 1. 5 14 2. 3 ‘ ‘2.3 4.0 1.0 ? 1.0 ? 1.0 ? Sisali dirty layer Yi—-’-’ very dirty layer Strat. Year 1960-61 1959-60 1958- 59 1957—58 1956- 57 APPENDIX 14 Annual Primary Stratification Statistics for the Intermediate Neve as Measured in 1960-61 Strat. Thickness jin feet of firn) 5300 Feet* 4900 Feet* 5300 Feet* 4900 Feet* 8fl6j60 811.7160 1961 1961 - - 12. 0 (est.) 10. 0 (est.) 4. 0 - - 4 0 - - OONO‘II-P- OOOO * Each site is on a 2° down-glacier gradient. 11.0 60:05 50 0.23002va .2303 600000 83030 mm 9” .8 0:0 00 0920802 0.00% N 08.20904 *1. .20 0o 2.80 0 .0880 .0 .2 . . .020 .8000 80.030 60.002 m000:0 00.30002 ... I +1 0000100050000 CID'd‘Nr—IOONOOO’) 'H O r—T * * + IOLOLDOLOLOOO r—ICN.CYD.(N.‘<1*NC\'J v-i 0002mm 00000 0:0 00 52 00 00020630”. 00.2% ma om om mm om Hm SN .50 Q Ammgofi as pcmfifisvm .2503 066660666 KDQOPCIDCDODCDCO cCal—‘1“!(DCDCDv—i'if‘C) om“ may. w 8389 500me am 20 22 0‘0- HHN'HN FD-HCYDQOONOCDOUDOO COOONNr-ICONN *m. .w A83 0008:. .m. 00\02\0 150 6 52 2.0 28263.2. 00.20 A .U . 6000.200 263030 @3332 .12.. mwnfiwma mwumwmfi wwumvmfi mwnwvma wwumwmfi Svnowma wvnbvma mwuwvmfi omumvmfi 5% 02020-00 02 mmnamma mmnmmma wmummma mmnwmma wmummmfi bmnmmma mmubmma mmummma ownmmma Hmuomma $183 000 «mama .83 .2 00.25032 00 962 .8304 05.1 no 000025 goomuommm 6.52 05 .8“ 0030305 6300Gfl02m. bgflfl #022104 ma NHQZMQAHAV .250 2.0.0.0 1111 Strat. Year and Firn Increment Beginning of 1961-62 Accumulation APPENDIX 16 Firn-Pack Statistics for the Gilkey Ne’ve’, Site 19A 6500-Foot Level Surface North of Mt. Ogilvie, 1961* Structure New Snow 1" Ice Stratum Old Snow 4" Depth-Hoar Stratum 1-2" Ice Stratum Depth (in feet} 0-1 1-2 Remarks 1961 Ablation Surface 1960-61 21. 5 Feet** 4 Thin Ice Strata 1" Ice Stratum l. 5" Ice Stratum 1960 Ablation Surface 1959- 60 6. 0 Feet 3. 5" Ice Stratum 12" Ice Stratum Notably Straticulated Notable Feature, Con- tinuous. Probably 1959 Ablation Surface 1958-59 4. 5 Feet 4" Ice Stratum Pronounced Depth- Hoar Stratum Much Diagenetic Ice at 30 Feet and Below Large Xtals, Hard Ice (cold?) with Diagenetic Quality: Many Air Bubbles; No H20 Pockets Very Large Xials. 1958 Ablation Surface Numerous Ice Strata Dominant 8" Ice Stratum * Data recorded 9/6 - 8/61. ** As opposed to 1'7. 5 feet on the crestal (BA-8B) ne/ve’. 1h2 Water Ice (clear), Few Bubbles. 1" Core with Dense Water Ice on Either Side; No Air Pockets; No Water Sacks. 'I‘ypifying Polar-Type Thermal Conditions APPENDD§ 17 Camp 8A - Firn Density Measurements (S. I. P. R. E. Corer),* September1 1961 Elev. 59 50 feet Depth (inches) 14-22 33-41 77-85 115-117 120-128 148-156 161-169 187-195 204-212 228-236 240-248 248-250 270-278 291-299 320-328 343-351 359-361 378-386 406-408 423-431 460—468 483-491 507 534 556 569 577 592 604 624 643 661 682 701 OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO Density (g_'rr_1[<:C) . 434 . 384 . 600 . 531 . 572 . 580 . 596 . 580 . 560 . 616 . 660 . 497 . 564 . 528 . 576 . 576 . 544 . 583 . 532 . 528 . 549 . 553 . 557 . 583 . 580 . 566 . 597 . 557 . 649 . 631 . 631 . 629 . 650 . 608 Egglacial Features 1 Inch Ice Stratum 2 Small Ice Layers . 75 Inch Ice Stratum H I! H- I! l H H II .25 II I! H H H I! H .50 I! H II 3 ” " ” (not weighed) Very Clear Ice . 50 H H I! . 38 H II I! 2 Ice Laminae Homogeneous I! H 3. 5 Inch Ice Strat. -Bubbly-Grades into Firn Homogeneous 3 Ice Laminae Ice. Strat. and Ice Laminae (not weighed) Homogeneous * Density samples obtained from 60-foot bore hole. 1113 APPENDIX 18 Camp 8A - Firn Density Measurements (500 cc Hand Corer),* September, 1961 Elev. 5950 feet Depth Density Inches (g_rr_1[cc) 12 O. 518 24 0. 540 36 0. 550 48 0. 556 60 0. 551 72 0. 558 84 0. 565 96 0. 563 108 0. 563 120 0. 586 132 0. 560 144 0. 558 156 0. 574 168 0. 572 180 0. 578 192 0. 534 Depth-Hoar Zone 204 O. 516 207 2" Ice Layer (1959-60 Ablation Surface) 209 0. 542 * Density samples obtained from east and west walls of test pit. lLLLL APPENDIX 19 Camp 9 - Firn DensitLMeasurements) August 1961 Elev. 5200 feet Depth Density* (inches) (gmgcc) 12 0. 508 24 O. 530 36 0. 496 48 O. 561 60 0. 621 72 O. 596 84 -0. 568 96 O. 598 108 O. 555 120 0. 568 132 O. 665 * Density samples taken from the wall of a test pit using a 500 cc hand corer. Each value is an average of 3 measurements. 1115 APPENDIX 20 Juneau Icefield Saline Content Record, 1960-61 PPM* Date Location Depth of Chloride 8/17/60 Camp 9 - 4900' 0 0. 7 8/ 60 Vantage Pk. Basin - 4050' 0 1. 1 8/60 Camp 8 O 0. 6 8/60 Camp 10B - 3500' 0 1. 4 8/60 Camp 9 O O. 5 8/60 Camp 9 0 O. 3 8/60 Camp 10 7 O 0. 3 9/8/61 Camp 19E - 6500' 0(new snow) 0. 9 15"(new snow) 1. O 20"(new snow) 1. 3 30"(new snow)** 2. 1 34"(60-61 firn) O. 1 9/8/61 6200' O 0.7 9/6-9/61 Camp 8A- 5950’ 6" 0. 7 10" O. 4 18" 0. 4 9/12/61 Camp 8A- 5950' 0 O. 7 3. 50' O. 4 4. 25' 0. 9 6. 50' 1. 1 12. 25' O. 9 9/9/61 5100’ 4" 1. 1 9/9/61 4600' 4" 1. 2 9/9/61 4200' 2" 0.9 * PPM = parts per million or milligrams per liter. ** Depth—hoar. lhé APPENDDiZl Camp 8 - Daily Temp_erature and Precipitation Record. 1961 Elev. 6800 feet Temp. (°FL Ppn. Date Max. Min. Avg. finches in 24 hrsg.) 7/27/61 58 54* 28 48* 29 39* 0.01 30 54 39 47 31 42 36 39 8/1/61 37 30 34 2 4O 36 38 0.30 3 37 34 36 0.28 4 39 35 37 0.09 5 38 35* 0. 58° 0. 71 snow 6 29 25* 12.0 (snow) 7 32 27* 8 40 27 34 9 39 31 35 10 34 32 33 0.03 11 36 32 34 0.12 12 37 35 36 1.32 13 40 33 37 1.87 14 32 30* 0.35; 0. 47 snow 15 41 32* 16 45 34* 17 51 42* 18 54 46* 19 56 49* 20 43 38* 21 34 33 34 22 33 32 33 0.08 23 36 0.18 24 35 34* 1.68 25 31 25 28 26 28 26 27 27 30 23 27 28 32 27 30 29 30 27 29 30 30 30* 31 32 30 31 * Extrapolated from Camp 10 records using a delta difference of -11°F. . . i. e. ,A- A i3. 7°F lapse rate per 1000 feet of elevation. 1147 lh8 Camp 8 - Daily Temperature and Precipitation RecordL 1961 (cont.) Temp. (° F) Ppn. Date Max. Min. Avg. (inches in 24 hrs.) 9/1/61 34 28 31 2 30 29 30 3 31 26 29 4 28 24 26 5 21 19 20 6 28 23 26 7 32 24 28 8 30 26 28 9 29 26 28 10 43 33* ll 53 41 47 12 40 38 39 13 41 (End of 1961 summer field season at Camp 8) APPENDDCZZ Camp 8A - DailLTemperature and Precipitation Record,_1961 Elev. 5950 feet Temp. (°F) Eh Date Max. Min. 7 Avg. 7/27/61 57* 28 51* 29 42* 30 50* 31 42* 8/1/61 37* 2 41* 3 39* 4 40* 5 38* 6 28* 7 30* 8 37* 9 38* 10 36* 11 37* 12 39* 13 40* 14 33* 15 35* 16 37* 17 45* 18 49* 19 52* 20 41* 21 37* 22 36* 23 24 37* 25 38 31* 26 32 30 31 27 37 26 32 28 44 30 37 29 35 29 32 30 33 26 30 31 36 31 34 Ppn. (anhes in 24 hrs; 3 3 (rain) (start of Camp 8A summer field 3. O snow season) 0.5 " 5.5 " 3.0 " 0.7 " * Extrapolated from Camp 8 records using a delta difference of +3. 4°F. . . i. e. , A13. 7°F lapse rate per 1000 feet of elevation. 149 150 Camp 8A - Daily Temperature and Precipitation Record, 1961 (cont.) Date 9/1/61 mTemp. (°F) Iflax. Nfin. .Avg. 41 3O 36 37 31 34 38 28 33 37 22 30 25 19 22 38 13 26 26 31* 26 31* 27 31* 24 36* 42 50* 34 42* Ppn. (inches in 24 hrs.) 3. 5 snow 5.0 " 6.0 ” (End of 1961 summer field season at Camp 8A) [£PPENNEHXI23 Camp 9 - Daily Temperature and Precipitation Record, 1961 Elev. 5200 feet 'Tenq;(°F) Date Max. Min. Avg. 7/27/61 64 48 56 28 56 51 54 29 39 46* 30 50* 31 47* 8/1/61 44* 2 42* 3 45* 4 46* 5 42* 6 32* 7 34* 8 40* 9 41* 10 41* 11 12 40* 13 43* 14 37* 15 39* 16 49 33 41 17 56 37 47 18 72 53* 19 59 56* 20 47 45* 21 52 40 46 22 43 40* 23 43 39 41 24 41 40 41 25 42 38* 26 35 32 34 27 42 35* 28 38 33 36 29 35 32 34 30 38 37* (inches in 24 hrs.) 11. NI—‘O 45(7/29-8/15) .18 .30 .50 .08 .59 .49 (end of 1961 summer field season at Camp 9) * Extrapolated from Camp 10 records using a delta difference of -4° F. . . i. e. , :t A 3. 7' F lapse rate per 1000 feet of elevation. 151 152 Camp 9 - Daily Temperature and Precipitation RecordL1961 (cont.) Temp. (°F) Ppn. Date Max. Min. Avg. (inches in 24 hrs.) 8/31/61 36* 9/1/61 38* 2 3 4 36* 5 34* 6 35* 7 33* 8 36* 9 37* 10 40* 11 46* 12 50* 13 51* 14 53* AJQPEHJEEXI24 Camp 10 - Daily Temperature and Precipitation Recorg 1961 Date 7/21/61 22 23 24 25 26 27 28 29 30 31 8/1/61 Elev. 4000 feet Temp. (in °F) Max. Min. Avg. 48 38 43 49 38 44 51 34 43 59 42 51 61 51 56 66 48 57 72 58 65 60 57 59 55 44 50 64 44 54 57 44 51 5O 45 48 48 43 46 53 44 49 55 45 50 46 45 46 37 35 36 42 33 38 50 37 44 50 39 45 47 43 45 45 47 41 44 47 46 47 42 40 41 50 35 43 50 39 45 63 43 53 62 51 57 61 59 60 52 46 49 48 45 47 48 39 44 46 47 43 45 47 37 42 39 36 38 45 33 39 153 Ppn. (inches in 24 hrs.) 000 CO 000 I—‘OOOOOO OONOO .04 .03 .06 .38 .05 .35 .82 .60 .41 .83 .30 .30 .16 .05 .47 .37 .21 .05 (start of 1961 summer field season) 151; Camp 10 - Daily Temperature and Precipitation RecordL 1961 (cont.) Date 8/28/61* 29 * 30 * 31 * 9/1/61 * 2 3 4 * 5 * 6 * 7 a: 8 * 9 * 10 * 11 * 12 * 13 * 14 * * Taken from thermograph charts. Temp. (in °F) Max. Min. Avg. 41 39 40 39 37 38 44 38 41 41 38 40 45 38 42 No record taken. No record taken. 42 42 43 40 43 45 48 57 59 61 63 38 34 34 34 36 36 40 42 48 48 50 40 38 39 37 40 41 44 50 54 55 57 Ppn. (inches in 24 hrs.) ** (end of 1961 summer field season) ** No record kept from 8/28-9/10/61, camp not occupied. Date 8/15/61 16 17 18 19 20 8/21-9/2 9/3/61 13 APPENDIX 25 Camp 8 - Duration of Sunshine Record, 1961 Elev. 6800 feet Duration (time) 0945-2030 1015-2030* 0810-2000 ' 0650-0710; 0825-2030 0815-1930 0820-2000 No Record 0725-0745; 0910-0915; 1205-1220 1155-1830 1130-1140; 1235-1340; 1355-1740 0730-1345;1620-1645 0955-1040; 1320-1445 0640-0710; 0840-0930; 0940-1750 No Record 0840-1800 0815-1900 0835-1855 0840-1500 (up to 1500 hrs.) * Not recorded from time of sunrise. 155 Total Hours 10. 50 10.25+ ll. 80 12. 40 11,. 25 11. 66 0. 66 6.60 5. 00 6. 66 2. 10 9. 50 9. 30 10. 75 10. 30 6. 30 Total Possible Hours 15. 5 15 14 13. 5 13 Date 7/21/61 22 23 24 25 26 27 28 29 30 31 8/1/61 APPENDIX 26 Camp 10; Daily Peak Solar Radiation Record, 1961 Elev. 4000 feet Peak Radiation (1p 1angleys)** .72 .60 .50 .46 .44 .44 .40 .41 . 21 .30 . 55 .10 . 11 .42 .85 .82 OOt—‘HHHHHHHHl—‘HHHI—‘H *-x-x-x-*-x-x-x-' (O N Date 8/15/61 16 17 18-24 25 26 27 28 29 30 31 9/1/51 Peak Radiation (in langlest * a: a: No chart record 0. 53 l. 00 1. 04 1. 50 1. 36 1. 52 1. 60 1. 01 0.73 .95 . 20 . 58 . 16 . 66 . 18 . 20 . 16 . 14 . 10 .11 . 06 t—‘HHHHHHOHHHO * Chart indicates instrument was not recording properly, hence values are probably erroneous. ** Langley = Gram calories per cm‘2 per hour. 156 APPENDIX 27 Mt. Juneau Daily Precipitation Record, 1961 Elev. 3576 feet (Ppn. in inches) g1 Luly August September 1 0 1.05 0. 70 2 0 3.50 2. 30 3 2. 42 0.65 0. 65 4 3.10 0 O. 25 5 3. 70 0 0 6 0.35 1. 80 0 7 2. 00 2.40 4. 80 8 1. 65 2. 95 0. 80 9 2. 85 0 0. 05 10 5. 15 0.70 0 11 0. 90* 5.15 0 12 M ? 6. 60 0 13 0 Misg. 0 14 0 Misg. 0 15 O 0 0 16 0 0 0 67 17 1. 50 0 0. 06 18 4. 45 0 1. 30 19 4. 85 0 0. 90 20 0.45 0 0 21 0.35 1. 30 0. 02 22 0 2. 95 0 23 0 6. 40 1. 70 24 0 1. 50 0. 45 25 0 0 0. 15 26 0 3. 15 0 27 0 0.63 0 28 0. 03 2. 35 End of program for 1961 29 O. 15 1. 42 30 0 0.35 31 0 2. 10 * Estimated 157 APPENDD(28 Annex Creek Daily Temperature and Precipitation Recordp 1961 Date 7/21/61 22 23 24 25 26 27 28 29 30 31 8/1/61 jElev. 24 feet Temp. (°F) Iflax. Nfin. Avg. 60 44 52 60 44 52 76 41 59 75 39 57 70 40 55 72 41 57 74 47 61 73 50 62 63 44 54 73 40 57 66 41 54 64 44 54 60 41 51 66 48 57 66 48 57 65 41 53 52 43 48 55 38 47 67 39 53 65 39 52 58 39 49 54 47 51 51 48 50 62 51 57 58 45 52 60 38 49 68 38 53 66 35 51 64 36 50 66 36 51 66 38 52 62 44 53 54 48 51 52 50 51 58 48 53 58 36 47 48 43 46 52 36 44 50 38 44 158 ijn. (inches in 24 hrs.) ONNUH-k HCDO OOO I—‘OO POO .11 .01 .77 .19 .81 .10 .62 .11 .79 .36 .75 .51 .71 .83 .48 .28 .97 (start of 1961 summer field season) 159 Annex Creek Daily Temperature and Precipitation Record, 1961 (cont.) Temp. (°F) Ppn. Date Max. Min. Avg. (inches in 24 hrs.) 8/29/61 48 40 44 0. 79 30 50 38 44 0. 11 31 48 40 44 0. 65 9/1/61 58 36 47 0. 37 2 50 48 49 0. 50 3 54 38 46 0. 81 4 54 38 46 0. 10 5 52 37 45 6 56 29 43 7 48 38 43 2. 08 8 53 38 46 ' 0. 67 9 56 38 47 10 56 32 44 11 54 32 43 12 56 38 47 13 56 38 47 14 60 36 48 (end of 1961 summer field seas on) APPENDIX 29 Juneau Daily Temperature and Precipitation Record, 1961 Elev. 72 feet Temp. (in ° F) Ppn. Date Max. Min. Avg. (inches in 24 hrs.) 7/21/61 63 50 57 0. 11 (start of 1961 summer 22 65 50 58 field season) 23 70 51 61 0. 02 24 74 47 61 25 77 42 60 26 77 52 65 27 80 54 67 28 80 54 67 29 70 55 63 T 30 72 51 62 31 72 52 62 T 8/1/61 71 56 64 0.01 2 60 53 57 0. 93 3 65 53 59 0. 13 4 65 * U 5 * 50 U 6 * * 1. 05 7 56 49 53 0. 48 8 64 46 55 0. 04 9 66 48 57 10 66 53 60 T 11 63 54 59 0. 87 12 59 49 54 3. 38 13 58 54 56 2. 11 14 57 53 55 3. 07 15 64 46 55 0. 37 16 68 49 59 17 65 45 55 18 68 48 58 19 70 48 59 20 71 49 60 21 69 52 61 0. 06 22 59 52 56 0. 32 23 55 52 54 2. 05 T - Trace, an amount too small to measure. U - Amount included in following measurement, time distribution unknown. * No record. 160 161 Juneau Daily Temperature and Precipitation Record, 1961 (cont.) Date 8/24/61 25 26 27 28 29 30 31 9/1/61 Temp. (in °F)_ Max. Min. Avg. 58 49 54 62 47 55 56 49 53 59 48 54 61 46 54 56 48 52 58 50 54 59 52 56 61 52 57 61 49 55 62 47 55 60 53 57 6O 45 53 57 38 48 55 50 53 56 48 52 58 47 53 65 42 49 65 43 54 67 43 55 69 45 57 69 45 57 Ppn. (inches in 24 hrs.) L OOH 0 000900000 % .m .% .M .M .M W .m .% .% .m .m .M .% (end of 1961 summer field season) APPENDIX 30 Juneau Airport Daily Temperature and Precipitation Recorpp 1961 iElev. 17 feet Temp. (°FL Ppn. Date Max. Min. Avg. (inches in 24 hrs; 7/21/61 61 46 54 0. 02 (start of 1961 22 63 47 55 summer field season) 23 71 46 59 24 73 44 59 25 76 45 61 26 77 47 62 27 79 49 64 28 70 48 59 0.02 29 68 50 59 0.02 30 78 46 62 31 67 47 57 T‘ 8/1/61 62 51 57 0.30 2 57 49 53 0.62 3 71 51 61 0.03 4 70 50 60 0.05 5 61 50 56 0.61 6 52 49 51 0.32 7 59 45 52 0.38 8 66 44 55 9 66 44 55 10 64 49 57 0.21 11 57 53 55 0.53 12 59 55 57 2.32 13 61 57 59 1.07 14 58 47 53 1.61 15 64 41 53 16 63 44 54 17 69 41 55 18 72 41 57 19 71 43 57 20 68 48 58 21 60 47 54 0.10 22 55 49 52 0.23 23 59 53 56 0.98 24 62 46. 54 0.45 25 59 43 51 T - Trace, an amount too small to measure. 162 163 Juneau Airport DailLTemperature and Precipitation Recordt 1961 (cont.) TemLCF) Ppn. Date Max. Min. Avg. (inches in 24 hrs p 8/26/61 52 42 47 0.90 27 60 41 51 'I‘ 28 53 45 49 0. 65 29 53 47 50 0. 36 30 55 39 47 O. 06 31 54 45 50 0. 53 9/1/61 63 45 54 0. 25 2 53 45 49 0. 58 3 55 44 50 0. 11 4 60 41 51 5 58 39 49 0. 09 6 59 33 46 T 7 57 46 52 1. 04 8 56 46 51 0. 01 9 58 42 50 T 10 62 38 50 11 60 36 48 12 61 36 49 13 61 38 5O 14 64 37 51 (end of 1961 summer field season) .05H0> H008 38:88 .8 8303200 .HoH 5085503 0.8000 EH00 * OO .O NO .O Ow .O Ow .O NO .O NO .O OH .O OO .O ON .O ON .O NH .O .o0Q OO .O OO .O NHV .O OHV .O OO .O NO .O NH .O OO .O OH .O ON .O .3 .O .>oZ OO .O OO .O 3 .O HO .O OO .O OO .O HVO .O NO .O HVN .O ON .O HO .O ...BO Ow .O OO .O OO .O H0 .O OO .O NO .O ON .O OO .O NH .O NN .O NN .O .HQ0O H0 .0 mm .o 8 .0 me .o S .0 H0 .0 mm .o 8 .o E .o om .o E .o .03. OO .O HO .O HO .O N .O NH .O OH .O HVH .O NH .O NO .O OH .O OH N ha. NN .O NH .O HO .O OH .O NO .O NO .O OH .O OH .O OH .O NH .O OO .O 03% ON .O OO .O NN .O ON .O OH .O NO .O «N .O OH .O OH .O ON .O NH .O 02 NO .O OH .O NH .O HNH .O ON .O NH .O OO .O OO .O OH .O ON .O N .O ..a< ON .O OO .O OO .O OH .O OO .O NH .O HH .O NH .O OO .O NN .O N .O .02 OO .O OH .O NN .O ON .O N .O ON .O NO .O NH .O OO .O NN .O NH .O .Q0nH N .O NO .O OO ”O HO .O , HVO .O OH .O ON .O NH .O S .O HH .O S .O .s0h 70.3 N E 0325 830058000 c002 O .NH O .OO O .OO O .sN O .ON O .ON O NH O SN O .HO O .NN H. .ON .o0Q H .NN N .HO O .OO .O .NO O SO O .OO N .NN H4 .OO O .HO O .OO N .NN .>oZ O .OO O .OH» H. .HHV O .Hw HV .OH. N .OO O .OO O .NH4 N .NHV N .OHV N. .OO .80 N .OHV O .NN O .NH» O .us O .HO O .3 O .00 O .OO H. .Ow * H .ON .30O H .OO O .NO N .NO O .NO O .OO H4 .3.» N .HO N. .OO N .NO * O .HO OE... 0 .OO O .NO O .OO O .OO O .OO .O .NO H SO O .OO N .OO * H SO fish O .OO H4 .HO H. .wO H .OO O .qu O .NN HV .HO * H .NO * H .HO 063. O .OH... 0 .OO O .5 O .OHV N .ON N .ON O .Nv O .us * * * 02 O .OH» O .NHV O .OO O .st O .OH» O .NHV N .OO O .OO O .HH. * * .0me N .NO O .NO O .OO H .OO O .OO O .HO N .NN * 0 .NO H .OO N .ON .002 O .ON O .OO O .NN O .ON O .ON H .NN N .NN O .ON O .OO H .ON N .NN .Q0HH w .NN O .HVN O .OH O .ON N .OH H4 .ON O .ON N .NH O .OH N .OH O .OH .Q0H. HONH OONH NO NH OONH HO NH OO NH OO NH H4O NH OO NH NONH HO NH at .9809 002 151. 00H HVN .>0Hm HOIHO NH @0090 20:88. .HoO 0.8on 80.838000 90 0930009809 3.582 0002 HO NHQH/Hmnmnjw ON .0 O3 .0 OO .O N.O .0 ON .O O3 .0 3O .0 OO .O OO .0 O3 .0 O3 .0 OO .O OO .0 ON .0 HO .O NO .0 ON .0 OO .O N.H .O NH .O OO .O HN .O OO .O NH .0 ON .0 OH .O HN .O NH .0 ON .0 HO .0 ON .0 OH .O NO .O NH .0 ON .O OO .O O .ON O .OO O .N.O O .OO O .N.O N. .OO O .H3 O .O3 3 .O3 3 .HO N .HO N .OO H .OO O .N.O N .3O N .OO O .OO O .OO , O .3O N. .OO H ..OO O .OO O .OO N .O3 O .H3 O .33 O .H3 N .OO H .3O O .OO H .OO N. .OO N. .NO H .3O O .HO O .ON HONH OONH NONH .05H0> 8008 38808 No 80308200 .88 8035398 0.8008 NHH0Q * OO .O N.N .O NO .O OO .0 ON .0 ON .O HH .0 N.N .O NH .O OO .O NO .0. ON .0 NOOOON3OO3©> OOOOONCSLOOOOO OOO3OLQOOO3OO (D L0 03' H mmmwmmmm‘d‘fi‘m NH .O O3 .O HH .O O3 .O O3 .0 OH .O 33 .O NO .O OH .O OO .O OH .O H3 .O ON .O .N3 .O O3 .O 3O .O NO .O OO .O HO .O 3N .O ON .O NN .O OO .O 3 .O OO .O O3 .O OO .O OH .O OO .O ON .O NO .O HH .O NO .O OH .O HH .O OH .O NO .O OH .O HH .O NO .O 3H .O NH .O NH .0 ON .O NO .0 3H .O 3H .O 3O .O NN .O OH .O . OH .O NH .O 3N .O ON .O OO ..O OH .O HO .O 3H .O NN .O NN .O ON .O HN .O N.N .O N3 .O H3 .O ON .O NO .O NO .O NN .O N.H .O NH .O HN .O 70.8 3N 8 008083 80308800 HQ 8002 O .NO N .N.N O .ON N. .OO N .OO N .O O .O3 O .NO O .NN 3 .H3 N .N.O 3 .O O .O3 O .NO O .H3 . O .33 O .O3 O .N. O .OO N .OO N .OO H .OO 3 .HO N .O N. .HO O .OO 3 .OO O .OO O .N.O 3 .O 3 .OO N .NO O .NO H .N.O N. .NO N. .N. H .OO O .NO N .NO O .OO N. .NO O .O O .OO H .O3 O .O3 O .OO N .OO O .O N .H3 O .N3 O .NO N .OO * O .O N .OO O .NO O .NO O .3O O .OO N. .3 H .NN N. .3N H .OO O .ON N .OO N .O O .ON H .ON O .3O O .ON O .ON O .NH N.ONH OONH OONH 3ONH OO NH NONH 3 av @805 8002 0.00% NN. .>0Hm HO: HONH 5008:” .88 Ogoomm GOSSHQHOPHQ O80 0830p0m805 3:802 8002 NO NHQZMQQHV NH .O NN .O OH .O OH .O NH .O OH .O COCONNCUODCDC‘OLOC‘Ou—IH ‘d‘LOCDOONO O O O I O O O O O O I I HHNWHN NLODODNHFC‘QHCOCD . . . o 0 000000 NNNVI‘WLQCOLOLOWC‘ON H Lf) C) H .00Q <62 0.00 .300 ..Ofiw 33... .D0HH .80N. 165 Mean Temp. (°F) 1955 Elev. 17 feet APPENDIX 33 Mean MonthlLTemperature and Precipitation Record for Juneau Airport, 19 51-61 1961 30. 5 27. 8 1960 19 59 18. 0 19 57 19 58 32. 8 20. 6 19 56 1954 19 53 1952 18. 5 19 51 J an. 31. 5 34. 39. 47. 4 52. 4 56. 3 53. 9 47. 7 40. 3 33. 4 31. 9 40. 9 49. 5 51. 1 54. 4 53. 3 49. 2 43. 5 34. 3 28. 2 33. 8 38. 8 46. 0 55. 2 54. 1 52. 6 48. 2 40. 3 34. 27. 1 32. 9 42. 5 48. 1 56. 5 57. 4 54. 5 47. 4 41. 1 25. 3 32. 8 38. 6 47. 9 54. 9 55. 5 57. 6 52. 4 41. 9 21. 8 28. 0 38. 7 45. 2 50. 0 56. 3 54. 0 48. 2 37. 5 29. 3 27. 8 38. 0 42. 9 50. 5 56. 8 52. 0 47. 0 38. 7 23. 6 ' 30. 8 33. l 46. 3 53. 8 54. 3 56. 1 49. 2 34. 3 31. 4 41. 0 49. 2 56. 3 57. 3 54. 9 49. 1 43. 2 V4. 30. 6 31. 5 37. 5 44. 7 52. 2 55. 5 54. l 48. 7 52. 2 21. 6 26. 0 39. 0 46. 8 60. 3 55. 5 50. 6 38. 0 Apr. May June July Aug. Sept. Oct. Mar. Feb. 30. 6 44. 9 42. 8 38. 33. 1 38. 21. 8 38. 4 37. 9 33. 9 32. 3 23. 5 31. 1 Nov. 166 30. 0 34. 9 29. 4 9 l8. 1 0. 13 0. 12 0. 15 0. 08 0. 16 0. 07 0. 08 0.07 0. 15 0. 05 0.06 0. 09 0. 05 0. 11 28. 1 Mean Precipitation (inches in 24 hrs.) 0. 05 0. 22 0. 12 0. 10 0. 08 0. 10 0. 11 0. 10 33. 3 22. 4 0. 07 Dec. J an. 0. 09 0. 13 0. 15 0. ll 0. 19 0. 40 0. 23 0. 33 0. 20 0. 13 0. 15 0. 11 0. 05 0. 12 0. 14 0. 15 0. 27 0. 29 0. l7 0. 24 0. 15 0. 04 0. 07 0. 13 0. 09 0. 14 0. 13 0. 17 0. 30 0. 04 0. 12 0. 08 0.15 7 N OH 0000 Mar. Feb. 0. 11 0. 12 0. 04 0. 24 0. 17 0. 19 0. 19 0. 14 0. 23 0. 19 0. 24 0. 05 0. 09 0. 05 0. 19 0. 13 0. 28 0. 12 0. 10 0. 16 0. 11 0. 10 0. 32 0. 15 0. 37 0. 31 0. 18 0. 24 0. 21 0. 09 0. 09 0. 04 O. 21 O. 17 0. 20 0. 19 0. 17 0. 10 0. 18 0. 21 0. 40 0. 09 0. 16 0. 12 0. 20 0. 08 0. 12 0. 19 0. 36 0. 43 0. 24 0. 09 . 11 0. 13 0. 09 0. 12 0. 12 0. l5 0. 08 Apr. May June July Aug. Sept. Oct. Nov. Dec. AINPEBHNDCB4 Mean January and Mean Annual Temperature Record for Annex Creek, Juneaui and Juneau Airport, 1940-61 Temp. (in °F) Juneau Annex Creek lflean JuneauHAirport lflean nnhu; Amun Jan. IRu lflean IRunnhuglflean lflean Ihnnflngjflean Jan. .Ann. Date . Ann. Jan .Ann. * Jan. Ann. Jan. .Ann. 25.0 40.4 23.7 40.9 Jan. 33.4 27.7 42.6* 34.0 42.7 22.8 41.2* 34.8 42.4- 18.2 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 36.4 44.8 31.6 41.1 mad33+aaaa CSCSéhfic» 343+3*aaab C>3*C>«>«) N'O'r—icx’lO «3030:0303 F40: 0303 .om m.m o.m ©.w o.m >.OH o.© Hmmfi omma w .2 m .3 mma wmm mmw mam 63:8. @802 oz * .0680 sofimd so cofigm mowwdmm Ho soflmfifimfi n .3 ma «3&3» o .N. 0 .mm OMH wmm H3» omw 3% NS H :8 m .m o .m 0 .ma mm ma >.m m.Hw HOH m.o> . mma w.om ¢¢m Ham Hmw mom pom wow mam mmH boa m.mm m.m m.m o.m m.H o.m o.m o.vH o.m bmma mama o s o .NN H .3 8m 54 an 02 e i. m .4 LOLOLQ LQNr-i mmmfl m .om * w .Et 0 .wm m .mm. com mmm mmm wmm mam wwm 034 * oam * m: * o .NH * m .H * o .N * o .m wmmfi mama 6H8 mmHmnoma 9822 Eggnog 58 com 53m 0 .OH 9 do 0mm mmw mwm $533 6.8on mwpmnoma @582 S82 Moopo 88mg mm. NHQmenjw o .m a .ma HOH mmm wow 3 ma .omQ .>oZ .30 comm $34. Eda mama .82 169 Date 1951 51-52 1952 52-53 1953 53-54 1954 54-55 1955 55-56 1956 56-57 1957 57-58 1958 58-59 1959 59-60 1960 60-61 1961 APPENDIX 37 Lemon Creek Mean Annual, and Mean Annual Maximum and Minimum Dischargg RecordL19 52-61 Mean Ann. Disch. (cfs) Calendar .1244. 148 * * 121 147 171 155 150 171 Water Year ** 122 184 * 130 140 161 165 146 166 201 Mean Ann. Max. Disch. (cfs) Mean Ann. Min. Disch. (cfs) 429 (Sept.) 515 (Aug. 346 (July) 447 (Aug.) 602 (Aug.) 544 (Sept.) 480 (July) 518 (July) 490 (July) 718 (Aug. 1 1. 0 (Feb.) 1. 5 (Mar.) * l. 5 (Mar.) 1. 5 (Mar.) 3. 0 (Mar.) 3. 5 (Mar.) 4. 0 (Feb. 8: Mar.) 5. 0 (Feb. 8; Mar.) - 8. 6 (Feb.) * Discharge records insufficient to calculate these values. ** Water year represents the period from 1 October - 30 September. 170 AIUPEEUDEK§RS Lemon Creek Daily Mean Discharge Record, * 1961 (discharge in cfs) Day April May June July August Saltember 1 56 779 280 418 400 2 46 764 287 530 560 3 42 422 432 606 535 4 41 355 680 555 331 5 40 436 740 674 236 6 41 470 590 722 173 7 37 386 515 746 565 8 35 339 445 500 716 9 38 355 495 335 396 10 46 319 987 339 284 11 54 301 875 626 242 12 50 294 1210 1750 261 13 73 267 740 2660 270 14 108 335 500 2130 267 15 16 116 315 418 980 236 16 18 124 267 414 445 400 17 12 140 274 414 301 264 18 10 136 432 786 290 515 19 9 142 455 966 287 560 20 10 126 343 798 280 294 21 11 111 294 525 284 192 22 12 98 294 440 418 148 23 14 123 301 386 1090 374 24 20 180 450 355 1730 400 25 26 138 378 373 722 242 26 30 134 355 391 595 175 27 37 150 315 436 427 119 28 46 136 319 445 422 94 29 50 146 343 440 520 146 30 55 161 304 450 427 209 31 280 445 450 * Stevens A-35 water-stage recorder used to measure stream discharge. 171 XI. W Ablation. The wasting or surface-lowering of a glacier by the combined processes of melting, evaporation, and sublimation. Amelioration. The total or partial dissipation, in the spring and’early summer, of the previous winter's cold wave in the surface zone of the firn-pack of a glacier, a result of the warming effect of the downward percolation of rat: and melt-water. Bergschrund. The crevasse occurring at the head of a glacier or margins of an icefield, which separates the moving firn and ice of the glacier from the relatively immobile firn and ice adhering to the headwall or nunatak. This crevasse commonly penetrates to the headwall or bed of the glacier. Bubbly glacier ice. The main material of glaciers variably containing air pockets and entrapped water bubbles, and having a density approximating 0.88-0.90 gm/cc. CAVU. Clear and visibility unlimited. A meteorologic term used to describe atmospheric conditions. Cirgue. A deep, steep-walled "amphitheatre" recess in a mountain, caused by glacial erosion. Dense glacier ice. Solid, unaerated ice at a density of 0.917 gm]cc., denoting great age and/or metamorphism. Depth-hoar. Stratum of relatively softer autumn snow lying just above the annual ablation surface, characterized by low density, cupshaped crystals. Diagenetic. A result of changes which take place in firn due to accumulation above it, or percolation of rain and melt-water through it; e.g. compaction and recrystalliza- tion. ~ Epeirogenic. Designating the broad uplift or depression of extensive areas of the earth's crust. Firn. Compacted, granular, but stilljgnwious "snow" in transition to glacier ice, characterized by a density approximating 0.50-0.75 gm./cc. Firn-ice. A mixture of partially altered firn and bubbly glacier ice (not a separate stage of metamorphosis), characterized by a density approximating 0.75-0.88 gm/cc. Firn-pack. The volume of retained firn accumulation of a glacier for any particular year or series of years. The 172 173 total firn component of a glacier. Glacier. A mass of snow, firn, and ice with definite lateral limits, with motion in a definite direction, and origi- nating from the compaction of snow by pressure. Isothermal. Having equal degrees of temperature. Katabatic wind. A wind that flows down slopes that_are cooled by radiation, the direction of flow being controlled topographically. Such a wind is the result of downward convection of cooled air. Local glacier condition. The end phase (or initial phase) just before complete disappearance of glaciers in cor- dilleran glaciation as depicted in the Taku District, Alaska-B.C. This condition is characterized by discon- nected glaciers or small icefield systems only at the highest elevations. Mean neve-line. The average elevation of the neve—line taken over a period of 10 years. Melt-water. Water resulting from the melting of snow, firn or glacier ice. Multiple ablation surface. A surface resulting from the complete ablation of—the annual accumulation each year for two or more successive years. névé. The accumulation area of a glacier. Neve-line. The elevation of the most stable position of the lower limit of firn or the nave. The demarkation divid- ing the areas of accumulation and dissipation. Nunatak. A hill or mountain which protrudes through the surface of a glacier. Polar glacier. A geophysical classification, characterized by perennially sub-freezing temperatures (-20°C or low- er) within the glacier, except for a shallow surface zone wihich may be warmed for a few weeks each year by seasonal atmospheric variations. Propagated surface water. Rain and melt-water produced on the surface ofia glacier. Regelation. The refreezing of ice which has melted under momentary pressure. Regime. The material balance of a glacier involving the otal-accumulation and the gross wastage in one budget year. The state of health of a glacier. 17h Retracted icefield condition. A stage of local proportion in cordilleran glaciation, with neve areas restricted to intermediate and high elevations. This condition applies to the Juneau Icefield at present. Semigpermanent neve-line. The elevation of the most stable position over a several year period. Snow-pack. The total snow component of a glacier from the current accumulation year. Sub—Polar glacier. A transitional phase in the geophysical classification of glaciers in which the penetration of seasonal warmth is restricted to a relatively shallow surface layer, but extends to greater depths than in the Polar glacier. Characterized by sub-freezing temperatures around -10°C. Sub-Temperate glacier. A transitional phase in the geophysical classification of glaciers in which the penetration of the winter cold wave is relatively deep, and may not be completely dissipated during the summer warming period. Tarn. A small mountain lake or pool that occupies an ice- gouged basin on the floor of a cirque._ Temperate glacier. A geophysical classification, character- ized by an’isothermal temperature at the pressure melt- ing point (0°C), below a recurring winter chill layer. Wisconsinan. The fourth and last stage of the Pleistocene epoch, extending from approximately 70,000 to 11,000 years ago, and including the last advance of the Pleistocene ice sheet. " ' ' 131:1“:51V " .- P _nl'd.! ..'.‘,‘ivg?.a,r,'.?i.J . 0.. V“. W -_ .- - . fit... IL; -. .: . } I jfi‘xfif' 3...... .- . ..3... . a u on I... I a......v.._.. . . ”3’- ....... nil...a, . . _ ..‘ . ..t o..»..-_..... .. b 91. ...fww .u... .-. .. o. I“ I)- .. .. — ' ‘ ' . . _ . f o ‘ .u . . o’pw. II I. .-. ‘ I ‘13-‘0‘ ,1. -6 . 3... 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