As ice sheets build up sea level drops, exposing continental shelves


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It is estimated that the ice sheets at their greatest extent required the evaporation of 50-60 million cubic kilometers from the oceans. The resulting decrease in sea level was approximately 121 m. This reduction in sea level would expose extensive continental shelves. This would have created a land bridge between present-day Alaska and Siberia, providing a possible avenue for early man to migrate from the Old World to the New World.


Credit: Museums Teaching Planet Earth; data from Peltier, W., 1993, Time Dependent Topography Through Glacial Cycle. IGBP PAGES/World Data Center-A for Paleoclimatology Data Contribution Series #93-015. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA.

For more info: http://vathena.arc.nasa.gov/curric/land/global/climchng.html