Deglaciation of North America

The Last Deglaciation of North America - 21,400 to 5700 years ago

The last Ice Age began about 120,000 years ago, and gradually intensified with lots of
variations over the next 100,000 years, reaching its maximum about 18,000 years ago.
The melt-back, between 18,000 and about 6000 years ago, was relatively rapid.

This movie shows how the great Canadian Ice Sheet melted away at the end of that last
Ice Age.

Credits

The Last Deglaciation of North America movie was created by Professor Tanya Atwater,
U.C.S.B., and Professor Stephen Porter, U. Washington using Photoshop and Morph.

Glacier reconstructions are based on Dyke, A. S. (2004), “An outline of North American
Deglaciation with emphasis on central and northern Canada” in Quaternary Glaciations-
Extent and Chronology, Part II, p. 373-424, J Ehlers and P. L. Gibbard, ed, Elsevier;
with additional data from Denton, G. H. and Hughes, T. J. (eds) 1981, The last great ice
sheets, p. 263-317. J. Wiley & Sons, New York, 484 p.

Coastlines and C14 calibration were estimated using the Barbados sea level curve of Bard
E, Hamelin BJ, Fairbanks RG, Zindler A (1990) “Calibration of the 14C timescale over
the past 30,000 years using mass spectrometric U-Th ages from Barbados corals”, Nature
345. p. 405–410.

Extent and variations of Great Basin lakes is from D. R. Curry, G. Atwood, and D.
Mabey, 1983, Major Levels of Great Salt Lake and Lake Bonneville, Map 73, Utah
Geological Survey: and from Morrison, R. D. (1965) “Quaternary geology of the Great
Basin”, in The Quaternary of the United States, H. Wright and D. Frey (eds), Princeton
University Press , and R. D. Morrison (1964) Lake Lahontan: Geology of the Carson
Desert, Prof. Paper 40 United States GeologicalSurvey..

Artist J. Iwerks assisted in rendering the glacial topography of the ice sheets.
Prof. J. Severinghaus provided helpful scientific critiques and suggestions.

Continental Map templates were constructed and down loaded from the ODSN Plate
Tectonic Reconstruction Service at
http://www.odsn.de/odsn/services/paleomap/paleomap.html

Full Downloads:

Quicktime (.mov)
26.8 mb

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