Analysis was conducted using US Coast Guard scanning, satellite photos, and other research data from 1973 to 2010. NOAA scientists found a significant downward trend in ice coverage for all of the lakes. Over the 38-year record, the overall ice coverage loss for all Great Lakes was 71%. Data from 1973 to 2010 indicated that:
- Lake Ontario had the highest ice coverage loss (88%);
- Lake Superior, the largest of the Great Lakes (31,700 mi2) had a 79% ice coverage loss; and
- Lake St. Clair, between Lake Erie and Lake Huron, had the smallest ice coverage loss (37%).
- Wang, Jia, Xuezhi Bai, Haoguo Hu, Anne Clites, Marie Colton, Brent Lofgren, 2012: Temporal and Spatial Variability of Great Lakes Ice Cover, 1973–2010*. J. Climate, 25, 1318–1329. doi: http://dx.doi.org/10.1175/2011JCLI4066.1
- US News on MSNBC.com. Great Lakes ice coverage falls 71 percent over 40 years.