The Great Lakes are mostly frozen over from a harsh, cold winter, and a new NASA photograph shows the stark beauty in magnificent detail.
During most winters, ice covers about half of the Great Lakes. This year is the first time since 1994 the massive bodies of water have been nearly entirely covered. According to the Great Lakes Environmental Research Laboratory, ice covers 88 percent of the water bodies. In 1994, coverage reached 94 percent.
The NASA Earth Observatory took an image of the Great Lakes from over 22,000 miles above the surface of our home world. The photo was taken on 19 February, and contains some surprising details.
Lake Superior is nearly completely covered in ice. This is normal, since this the northern-most of the natural features. More surprising is the southern-most lake, Erie, which has more ice cover than some waters to the north, including Lake Ontario. This is due to the depth of water, which is relatively shallow in Erie. Lake Michigan is largely free from obstruction.
Also visible in the NASA image are cracks in the ice, created by icebreakers to allow commercial shipping.
Widespread freezing of the Great Lakes may alter local weather patterns. As storms pass over the Great Lakes, they can usually pick up large quantities of moisture. This can dump large quantities of precipitation on areas to the east, including Buffalo, New York. With the waters largely frozen, this effect is lessened, and storms should have less moisture to dump. That fact has not stopped the area - and the northeast in general - from experiencing a great number of storms, along with extreme cold, this season.
"Persistently low temperatures across the Great Lakes region are responsible for the increased areal coverage of the ice. Low temperatures are the dominant mechanism for thickening the ice, but secondary factors like clouds, snow, and wind also play a role," Nathan Kurtz, from NASA's Goddard Space Flight Center, said.
Researchers believe the ice buildup will reduce evaporation off the Great Lakes during the winter months. This could raise water levels significantly when frozen surfaces melt in spring. This could be good news for local water supplies, as well as shipping. For now, it is icebreakers who are benefiting, seeing four times their normal workload.
The Great Lakes hold one-fifth of the world's supply of fresh water. For the first time in five years, travelers are able to walk over Lake Superior. More than 35,000 people have already made the journey to explore spectacular ice formations in caves located there.
The wintery photo was taken by the Aqua satellite. That mission launched in 2002, to explore the water cycle of Earth.
