Photo: NASA Goddard Space Flight Center
Researchers at Washington University have identified the main causes of huge holes in the ice cover off the coast of Antarctica. About it reported in a press release on Phys.org.
The researchers analyzed satellite images of sea ice, as well as data obtained with robotic probes and sea elephants are equipped with sensors. It turned out that the hole in the ice away from the shore arise from a combination of factors, including unusual conditions in the ocean and intense storms, which overwhelm the Weddell sea.
When the winds surrounding Antarctica, starting to blow closer to shore, in the Eastern part of the Weddell sea have intensive ascending streams from the sea water. Underwater hill Mod Rise creates major turbulence of this flow. When the surface layer of the ocean increases salinity, the winter storm may cause overturning circulation. Warm salty water comes to the surface, cools and becomes more dense, and then falls. The result is a feedback loop that prevents the formation of ice.
Ice Mod-Rise was seen in 2016-2017, when sea ice reaches maximum thickness. In September 2017 it area reached 9500 square kilometers and during the month rose to 80 thousand square kilometres. In the early summer months when the ice began to retreat, the ice merged with the open ocean. This phenomenon was also observed in the 1970-ies.
Video, photo All from Russia.