The Great Lakes ice cover is nearing 1979 records, which comes as no surprise considering the fact bone-chilling Polar Vortex temps have blanketed half the nation with off and on deep freezes all winter long.
According to Wired News on Wednesday, all five Great Lakes are nearly enclosed in ice, with about 84 percent of the lakes covered on average. A peak ice coverage came earlier this year, when ice covered 92 percent of the lakes. The record came in 1979 however, when 95 percent of the lakes were concealed by ice.
“Persistently low temperatures across the Great Lakes region are responsible for the increased areal coverage of the ice,” Nathan Kurtz, a cryospheric scientist at NASA’s Goddard Flight Center, said in a report by phys.org. “Low temperatures are also the dominant mechanism for thickening the ice, while secondary factors like clouds, snow, and wind also play a role.”
Lake Michigan set an individual record Saturday, when officials said the lake was 93.3 percent covered, breaking the previous record set in 1977.
In the last 20 years, the winter Lakes have generally had fairly little ice, with the 5 percent coverage in 2012 being the second lowest on record (the record low was in 2002.) Ice helps prevent water from evaporating in the winter from the Lakes so the overall lack of freezing has actually meant record-low summer water levels.
The widespread ice coverage will have implications moving into this spring as well, officials said.
Lake-effect snowfall amounts in the Great Lakes area are dictated by open ice. When the lakes are mostly open, cold winter moving over the lakes combines with warmer lake water moisture, resulting in large bands of snow and blizzards that pound the leeward side of the lakes on the eastern and southern shores.