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New evidence for high discharge to the Chukchi shelf since the Last Glacial Maximum

Published online by Cambridge University Press:  20 January 2017

Jenna C. Hill*
Affiliation:
Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093-0208, USA
Neal W. Driscoll
Affiliation:
Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093-0208, USA
Julie Brigham-Grette
Affiliation:
Department of Geosciences, University of Massachusetts, Amherst, MA 01003, USA
Jeffrey P. Donnelly
Affiliation:
Geology and Geophysics Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
Paul T. Gayes
Affiliation:
Center for Marine and Wetlands Studies, Coastal Carolina University, Conway, SC 29526, USA
Lloyd Keigwin
Affiliation:
Geology and Geophysics Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
*
*Corresponding author. Fax: +1 858 534 3310.E-mail address:[email protected] (J.C. Hill).

Abstract

Using CHIRP subbottom profiling across the Chukchi shelf, offshore NW Alaska, we observed a large incised valley that measures tens of kilometers in width. The valley appears to have been repeatedly excavated during sea level lowering; however, the two most recent incisions appear to have been downcut during the last sea level rise, suggesting an increase in the volume of discharge. Modern drainage from the northwestern Alaskan margin is dominated by small, low-discharge rivers that do not appear to be large enough to have carved the offshore drainage. The renewed downcutting and incision during the deglaciation and consequent base level rise implies there must have been an additional source of discharge. Paleoprecipitation during deglaciation is predicted to be at least 10% less than modern precipitation and thus cannot account for the higher discharge to the shelf. Glacial meltwater is the most likely source for the increased discharge.

Type
Research Article
Copyright
University of Washington

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References

Brigham-Grette, J. (2001). New perspectives on Beringian Quaternary paleogeography, stratigraphy and glacial history. Quaternary Science Reviews 20, 1524.CrossRefGoogle Scholar
Brigham-Grette, J., Lozhkin, A.V., Anderson, P.M., and Glushkova, O.Y. (2004). Paleoenvironmental conditions in western Beringia before and during the Last Glacial Maximum.Madsen, D.B. Entering America: Northeast Asia and Beringia before the Last Glacial Maximum University of Utah Press, Salt Lake City.2961.Google Scholar
Childers, J.M., Kernodle, D.R., and Loeffler, R.M. (1979). Hydrologic reconnaissance of western Arctic Alaska, 1976 and 1977. U.S. Geological Survey Open-File Report 79699.Google Scholar
Christie-Blick, N., and Driscoll, N.W. (1995). Sequence Stratigraphy. Annual Review of Earth and Planetary Sciences 25, 451478.CrossRefGoogle Scholar
Dalrymple, R.W., Boyd, R., and Zaitlin, B.A. (1994). Incised-valley systems: Origin and sedimentary sequences. Society for Sedimentary Geology Special 51.Google Scholar
Edwards, M.E., Mock, C.J., Finney, B.P., Barber, V.A., and Bartlein, P.J. (2001). Potential analogues for paleoclimatic variations in eastern interior Alaska during the past 14,000 yr: atmospheric-circulation controls of regional temperature and moisture responses. Quaternary Science Reviews 20, 189202.CrossRefGoogle Scholar
Fairbanks, R.G. (1989). A 17,000-year glacio-eustatic sea level record; influence of glacial melting rates on the Younger Dryas event and deep-ocean circulation. Nature 342, 637642.Google Scholar
Grosswald, M.G., and Hughes, T.J. (2004). Chlorine-36 and 14C chronology support a limited last glacial maximum across central Chukotka, northeastern Siberia, and no Beringian ice sheet; discussion. Quaternary Research 62, 223226.Google Scholar
Hamilton, T.D. (2001). Quaternary, glacial, lacustrine, and fluvial interactions in the western Noatak Basin. Quaternary Science Reviews 20, 371391.Google Scholar
Keigwin, L.D., Donnelly, J.P., Cook, M.S., Driscoll, N.W., and Brigham-Grette, J. (2006). Rapid sea-level rise and Holocene climate in the Chukchi Sea. Geology 34, 861864.Google Scholar
Manley, W.F., and Kaufman, D.S. (2002). Alaska PaleoGlacier Atlas. Institute of Arctic and Alpine Research (INSTAAR),. University of Colorado,, http://instaar.colorado.edu/QGISL/ak_paleoglacier_atlas., 1, .Google Scholar
Manley, W.F. (2001). Alaska North Slope 100 m Digital Elevation Model (DEM). National Snow and Ice Data Center. Digital media, Boulder, CO.Google Scholar
Mann, D.H., Peteet, D.M., Reanier, R.E., and Kunz, M.L. (2002). Response of an arctic landscape to Lateglacial and early Holocene climatic changes: the importance of moisture. Quaternary Science Reviews 21, 9971021.Google Scholar
Marren, P.M. (2005). Magnitude and frequency in proglacial rivers: a geomorphological and sedimentological perspective. Earth-Science Reviews 70, 203251.Google Scholar
McManus, D.A., Creager, J.S., Echols, R.J., and Holmes, M.L. (1983). The Holocene transgression of the flank of Beringia: Chukchi valley to Chukchi estuary to Chukchi Sea.Masters, P.M., Flemming, N.C. Quaternary coastlines and marine archaeology: towards the prehistory of land bridges and continental shelves Academic Press, London.365388.Google Scholar
Mock, C.J., and Anderson, P.M. (1997). Some perspectives on the late Quaternary paleoclimate of Beringia.Isaacs, C.M., Tharp, V.L. Proceedings of the thirteenth annual Pacific climate (PACLIM) workshop.Google Scholar
Posamentier, H.W., and Vail, P.R. (1988). Sea-level changes: an integrated approach. Society of Economic Paleontologists and Mineralogists Special Publication 42, 125154.Google Scholar
Phillips, R.L., Barnes, P., Huner, R.E., Reiss, T.E., and Rearic, D.M. (1988). Geologic investigations in the Chukchi Sea, 1984, NOAA ship SURVEYOR cruise.. U.S. Geological Survey Open-File Report 88-25.Google Scholar
Schumm, S.A., Mosley, M.P., and Weaver, W.E. (1987). Experimental fluvial geomorphology. Wiley, New York.413 pp.Google Scholar