The Great Lakes Are Ice-Free After Seven Months

At 11:25 a.m. on Wednesday, June 11, 2014, the Great Lakes were officially declared ice-free after seven months of frozen conditions on the waters. The National Oceanic and Atmospheric Administration (NOAA) reported the news today.

The last of the Great Lakes to completely thaw was Lake Superior. At one point during the winter, 92.19% of the lakes were covered - the second highest percentage on record and the highest since 1994. NASA provided much of the imagery via satellite technology, through the use of the Moderate Resolution Imaging Spectrodiameter (MODIS) instrument.

Throughout the 2013-2014 winter, the U.S. Coast Guard spent over 2,000 hours conducting ice-breaking operations in order to prevent commerce being disrupted through the lakes' numerous channels and harbors. The Great Lakes shipping season is lasts for 42 weeks out of the year in which over 150 million tons of shipments are delivered. 12 of the 42 weeks require icebreaking services to free up lanes for boats and ships.

"Water takes longer to warm up and cool down compared to air so there is always a delay from the lakes warming up than the air temperature," said Dayna Vettese, a meteorologist of the Weather Network, in this Toronto Star article. "Water requires more energy to heat up or cool down. Because this winter was so cold and so much ice was able to build up, it takes that much longer to melt and break apart all of that ice."

The ice cover of the Great Lakes is a serious issue because it affects commerce, hydropower, and the fishing industry. In order to avoid problems before entering the winter, the NOAA's Great Lakes Environmental Research Laboratory conducts extensive research in order to predict ice coverage of the lakes. This is all determinant upon climate patterns, lake water levels, water movement patterns, water temperature structure, and spring plankton booms.

The lake's ice coverage was still fairly significant over Memorial Day weekend. It was reported that ice chunks on Lake Superior were large enough to provide immense backdrops for sunbathers. Officials are hoping this coming winter won't cause as many issues as this year.