21,400 - 5700 years ago, animation
The most recent Ice Age began about 120,000 years ago, and gradually intensified with lots of
variations over the next 100,000 years. It reached its maximum about 18,000 years ago.
The melt-down was much more rapid, occurring between 18,000 and about 6000 years ago,
i.e., a span of only about 12,000 years. This movie shows how the great Canadian Ice
Sheet melted away at the end of that last Ice Age.
To view this movie, click on the image.
The glacier reconstructions and most coastlines are from the map set in 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, eds, 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.
Extents and variations of lakes in the Great Basin are 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, U.S. Geol.
C14 calibrations and coastlines not included on Arthur Dyke's maps 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.
Artist J. Iwerks assisted in rendering the glacial topography of the ice sheets.
Continental Map templates are from O.D.S.N. Plate Tectonic Reconstruction Service at
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