The Ungava Peninsula in northern Quebec appeared as a vast expanse of white surrounded by the dark waters of the Hudson Bay, Hudson Strait and Ungava Bay in late November 2012. The coastal fringe of this Northern Arctic region is sparsely populated (about 1500 residents), but the interior is an uninhabited plateau, underlain by layer of permafrost which measures 200-600 meters (650 - 1,968 feet). Winter mean temperature registers at -20°C (-4°F), with lows of -50°C (-58°F)relatively common.
Although people are scarce, wildlife thrives inland, including caribou, wolverine, Arctic hare, fox and polar bear. Waterfowl and other birdlife is abundant. In the frigid waters, marine mammals such as walrus, seal and whale can be found.
On November 25 the Moderate Resolution Imaging Spectroradiometer aboard NASA’s Aqua satellite captured this true-color image of the icy land of permafrost. The entire peninsula appears bright white, except for two circular areas, which appear as blue-black as the surrounding bodies of water. These are, in fact, two ice-free crater lakes. The smaller, more northerly lake is Pingualuit, and Couture lies in the south.
Both craters were formed millions of years ago by meteorites striking the surface, and today they hold deep lakes. Couture is approximately 8 kilometers (5 miles) wide and has a water depth of 150 meters (490 feet); Pingualuit’s lake is about 3 kilometers (2 miles) across and has a depth of 246 meters (807 feet).
These lakes do freeze in the winter, and are usually frozen by late November. Pingualuit usually has open water for just six to eight weeks in August and September. Freeze-up in these lakes depends on wind-driven mixing of the water, and overturning of the deep water column. Increased movement of the water delays freezing. Another factor in the late freezing may be an unseasonably warm summer this year. Meteorological records from Environment Canada show the average temperatures at weather stations near the lakes have been above normal for every month since July.