Following more than two decades of Arctic sea ice thinning and melting, an unusual event just weeks before the start of the spring melt season is providing visual proof of how vulnerable the ice pack really is.
During the end of February and continuing into early March, large fractures in the sea ice were observed off the north coast of Alaska and Canada, from near Ellesmere Island in the Canadian Arctic to Barrow, Ala., the northernmost city in the U.S.
The rapid climate change in the Arctic and sharp decline of sea ice has been attributed to manmade global warming, along with natural climate variability, and projections show the region becoming seasonally sea ice free by midcentury.
According to the National Snow and Ice Data Center (NSIDC) in Boulder, Colo., this fracturing event appears to be related to a storm that passed over the North Pole on Feb. 8, 2013, creating strong off-shore ice motion. The event is unusual but not unheard of, as similar patterns were seen in early 2011 and 2008. However, the NSIDC said the fracturing this time is more extensive.
The NSIDC said the fracturing is likely a sign of the prevalence of young and thin sea ice, which can be disturbed more easily by weather patterns and ocean currents, and also melts more easily when exposed to warm air and ocean temperatures during the melt season. As Arctic sea ice extent has plummeted since 1979, down to a record low in September 2012, first-year ice has become much more common across the Arctic, as thick, multiyear ice has declined.
“The large area of fractured ice is located in predominantly first-year ice, which is thinner and easier to fracture than thick, multiyear ice,” the NSIDC said on its website. More
