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Debris-Covered Glaciers in the Sierra Nevada, California, and Their Implications for Snowline Reconstructions

Published online by Cambridge University Press:  20 January 2017

Douglas H. Clark ,
Malcolm M. Clark  and
Alan R. Gillespie
Douglas H. Clark
Affiliation:
Department of Geological Sciences, AJ-20, University of Washington, Seattle, Washington 98195 E-mail:doug@oz.geology.washington.edu
Malcolm M. Clark
Affiliation:
U.S. Geological Survey, M/S 977, 345 Middlefield Road, Menlo Park, California 94025
Alan R. Gillespie
Affiliation:
Department of Geological Sciences, A J-20, University of Washington, Seattle, Washington 98195
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Abstract

Ice-walled melt ponds on the surfaces of active valley-floor rock glaciers and Matthes (Little Ice Age) moraines in the southern Sierra Nevada indicate that most of these landforms consist of glacier ice under thin (ca. 1 - 10 m) but continuous covers of rock-fall-generated debris. These debris blankets effectively insulate the underlying ice and greatly reduce rates of ablation relative to that of uncovered ice. Such insulation explains the observations that ice-cored rock glaciers in the Sierra, actually debris-covered glaciers, are apparently less sensitive to climatic warming and commonly advance to lower altitudes than do adjacent bare-ice glaciers. Accumulation-area ratios and toe-to-headwall-altitude ratios used to estimate equilibrium-line altitudes (ELAs) of former glaciers may therefore yield incorrect results for cirque glaciers subject to abundant rockfall. Inadvertent lumping of deposits from former debris-covered and bare-ice glaciers partially explains an apparently anomalous regional ELA gradient reported for the pre-Matthes Recess Peak Neoglacial advance. Distinguishing such deposits may be important to studies that rely on paleo-ELA estimates. Moreover, Matthes and Recess Peak ELA gradients along the crest evidently depend strongly on local orographic effects rather than latitudinal climatic trends, indicating that simple linear projections and regional climatic interpretations of ELA gradients of small glaciers may be unreliable.

Type
Articles
Information
Quaternary Research , Volume 41 , Issue 2 , March 1994 , pp. 139 - 153
Copyright
University of Washington

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References

Barsch, D. (1992). Permafrost creep and rockglaciers. Permafrost and Periglacial Processes 3, 175–188.CrossRefGoogle Scholar
Bateman, P. C. (1965). Geology and tungsten mineralization of the Bishop District California. U.S. Geological Survey Professional Paper 470, 208.Google Scholar
Bateman, P. C. (1992). Plutonism in the central part of the Sierra Nevada batholith, California. U.S. Geological Survey Professional Pa-per 1483, 186.Google Scholar
Birman, J. H. (1964). Glacial geology across the crest of the Sierra Nevada, California. Geological Society of America, Special Paper 75.CrossRefGoogle Scholar
Bozhinskiy, A. N. Drass, M. S., and Popovnin, V. V. (1986). Role of debris cover in the thermal physics of glaciers. Journal of Glaciology 32, 255–266.CrossRefGoogle Scholar
Bull, C., and Marangunic, C. (1968). Glaciological effects of debris slide on Sherman Glacier. In “The Great Alaska Earthquake of 1964: Hydrology” (National Research Council), National Academy of Sciences Publication 1603, pp. 309–317.Google Scholar
Burbank, D. W. (1991). Late Quaternary snowline reconstructions for the southern and central Sierra Nevada, California and a reassessment of the “Recess Peak Glaciation.” Quaternary Research 36, 294–306.CrossRefGoogle Scholar
Calkin, P. E. Haworth, L. A., and Ellis, J. M. (1987). Rock glaciers of central Brooks Range, Alaska, U.S.A. In “Rock Glaciers” (Giardino, J. R. Schroder, J. F. Jr., and Vitek, J. D., Eds.), pp. 65–82. Allen & Unwin, Boston.Google Scholar
Capps, S. R. Jr., (1910). Rock glaciers in Alaska. Journal of Geology 18, 359–375.CrossRefGoogle Scholar
Foster, H. L., and Holmes, W. G. (1965). A large transitional rock glacier in the Johnson River area, Alaska Range. U.S. Geological Survey Professional Paper 52S-B, B112–B116.Google Scholar
Gillespie, A. R. (1982). “Quaternary Glaciation and Tectonism in the Southeastern Sierra Nevada, Inyo County, California.” Unpublished Ph.D. dissertation, Caltech, Pasadena, CA.Google Scholar
Gillespie, A. R. (1991). Testing a new climatic interpretation for the Tahoe glaciation. In “Natural History of Eastern California and Highaltitude Research. White Mountain Research Station Symposium Volume 3” (Hall, C. A. Doyle-Jones, V., and Widawski, B., Eds.), pp. 383–398. University of California, Los Angeles.Google Scholar
Haeberli, W. (1985). Creep of mountain permafrost: Internal structure and flow of Alpine rock glaciers. Mitteilungen der V ersuchsanstalt fiir Wasserbau, Hydrologie und Glaziologie [Zurich], 77, 142.Google Scholar
Kesseli, J. E. (1941). Rock streams in the Sierra Nevada, California. Geographical Review 31, 203–227.CrossRefGoogle Scholar
Leonard, E. M. (1984). Late Pleistocene equilibrium-line altitudes and modern snow accumulation patterns, San Juan Mountains, Colorado, U.S.A. Arctic and Alpine Research 16, 65–76.CrossRefGoogle Scholar
Loomis, S. R. (1970). Morphology and ablation processes on glacier ice. Part I. Morphology and structure of an ice-cored medial moraine, Kaskawulsh Glacier, Yukon. Arctic Institute of North America Research Paper 57, 1–65.Google Scholar
Lundstrom, S. C. (1991). Near surface englacial debris concentration and distribution in alpine glacial systems: A significant factor in estimates of late Quaternary climate change. Geological Society of America Abstracts with Programs 23, A60.Google Scholar
Lundstrom, S. C. McCafferty, A. E., and Coe, J. A. (1993). Photogrammetric analysis of 1984-89 surface altitude change of the partially debris-covered Eliot Glacier, Mount Hood, Oregon, U.S.A. Annals of Glaciology 17, 167–170.CrossRefGoogle Scholar
Matthes, F. E. (1942). Glaciers. In “Physics of the Earth. Part 9. Hydrology” (Meinzer, O. E., Ed.), pp. 149–219. McGraw-Hill, New York.Google Scholar
Matthes, F. E. (1948). Moraines with ice cores in the Sierra Nevada. Sierra Club Bulletin 33, 87–96.Google Scholar
Meierding, T. C. (1982). Late Pleistocene glacial equilibrium-line altitudes in the Colorado Front Range: A comparison of methods. Quaternary Research 18, 289–310.CrossRefGoogle Scholar
Nakawo, M., and Young, G. J. (1982). Estimate of glacier ablation under a debris layer from surface temperature and meteorological variables. Journal of Glaciology 28, 29–34.CrossRefGoogle Scholar
Østrem, G. (1959). Ice melting under a thin layer of moraine and the existence of ice in moraine ridges. Geografiska Annaler 41, 228–230.CrossRefGoogle Scholar
Outcalt, S. I., and Benedict, J. B. (1965). Photo interpretation of two types of rock glacier in the Colorado Front Range, U.S.A. Journal of Glaciology 5, 849–856.CrossRefGoogle Scholar
Paterson, W. S. B. (1981). “The Physics of Glaciers,” 2nd ed. Pergammon, New York.Google Scholar
Porter, S. C. (1975). Glaciation limit in New Zealand’s Southern Alps. Arctic and Alpine Research, 7, 33–37.CrossRefGoogle Scholar
Porter, S. C. Pierce, K. L., and Hamilton, T. D. (1983). Late Pleistocene glaciation in the western United States. In “Late Quaternary Environments of the United States” (Porter, S. C., Ed,), pp. 71–111. Univ. of Minnesota Press, Minneapolis.Google Scholar
Post, A. (1967). Effects of the March 1964 Alaska earthquake on glaciers. U.S. Geological Survey Professional Paper 544-D.CrossRefGoogle Scholar
Potter, N. (1972). Ice-cored rock glacier, Galena Creek, Northern Absaroka Mountains, Wyoming. Geological Society of America Bulletin 83, 3025–3058.CrossRefGoogle Scholar
Scuderi, L. A. (1984). “A Dendroclimatic and Geomorphic Investigation of Late-Holocene Glaciation, Southern Sierra Nevada, California.” Unpublished Ph.D. dissertation, University of California, Los Angeles.Google Scholar
Thompson, W. F. (1962). Preliminary notes on the nature and distribution of rock glaciers relative to true glaciers and other effects of the climate on the ground in North America. In “Symposium at Obergurgl” (Ward, W., Ed.), International Association of Scientific Hydrology Publication 58, 212–219, Obergurgl, Austria.Google Scholar
Wahrhaftig, C., and Cox, A. (1959). Rock glaciers in the Alaska Range. Geological Society of America Bulletin 70, 383–436.CrossRefGoogle Scholar
Whalley, W. B. (1974a). Rock glaciers and their formation as part of a glacier debris-transport system. Geographical Papers 24, Geography Department, University of Reading.Google Scholar
Whalley, W. B. (1974b). Origin of rock glaciers. Journal of Glaciology 13, 323–324.CrossRefGoogle Scholar
Weather Bureau, U.S. Department of Commerce (1964). Climates of the States, California. Climatography of the United States 86-4, 139.Google Scholar
White, S. E. (1976). Rock glaciers and block fields, review and new data. Quaternary Research 6, 77–97.CrossRefGoogle Scholar
Barsch, D. (1988). Rockglaciers. In “Advances in Periglacial Geomorphology” (Clark, M. J., Ed.), pp. 69–90. Wiley, New York.Google Scholar
Yount, J. C. Birkeland, R W., and Burke, R. M. (1982). Holocene glaciation, Mono Creek, central Sierra Nevada, California. Geological Society of America Abstracts with Programs 14, 246.Google Scholar