Some stunning images of the Great Lakes have been captured this winter, as large portions of the massive bodies of water frozen were almost completely froze over for the first time in two decades.
The intense cold snap that gripped much of central Canada and the United States throughout the winter brought thick and widespread ice to the Great Lakes region.
Ice cover on North America’s Great Lakes reached 88 percent in mid-February 2014 -- levels not observed since 1994. The above photo was captured on Feb. 19, 2014. (NASA)
A convoy of Great Lakes cargo ships line up to follow an icebreaker on the St. Marys River, which links Lakes Superior and Huron on Jan. 9, 2014 in this photo provided by the U.S. Coast Guard. (AP / U.S. Coast Guard, Lt. David Lieberman)
Though parts of the lakes freeze every winter, earlier this month the ice cover topped 88 per cent. The last time there was this much ice was two decades ago, in 1994, when 90 per cent of the lakes froze. As of Feb. 21, 69 per cent of the Great Lakes were covered with ice.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired this image of Lake Erie in the early afternoon of January 9, 2014, when it was reported that 90 per cent of the lake was ice covered. (NASA)
Looking at data dating back to 1973, the average maximum ice extent has been just over 50 per cent. It surpassed the 80-per-cent mark just five times in the past four decades. The lowest average ice extent occurred in 2002, when only 9.5 percent of the lakes froze.
Grand Marais Observation Platform on Lake Superior froze over in February 2008. (NOAA Great Lakes Environmental Research Laboratory)
Persistently low temperatures across the Great Lakes region are responsible for the increased ice this year, according to Nathan Kurtz, cryospheric scientist with NASA's Goddard Space Flight Center."Low temperatures are the dominant mechanism for thickening the ice, but secondary factors like clouds, snow, and wind also play a role."
"We had an early ice season this year, owing to cold temperatures in the fall and early winter," said George Leshkevich, of NOAA’s Great Lakes lab. "Ice was reported on bays and harbors of the Great Lakes as early as the end of November, as opposed to the normal timing of mid-December."
The icebreaker Biscayne Bay passes Chicago's Navy Pier, left, as it through the ice covered waters of Lake Michigan on its way to Indiana on Feb. 12, 2014. (AP / U.S. Coast Guard, Chief Petty Officer Alan Haraf)
