A part of Antarctica once believed to be safe is now showing some signs of instability. There’s a substantial ice loss in recent years which could lead to the rising of sea water
Armed with information from satellite print outs which include those of the European Space Agency’s CryoSat-2 satellite, the sole function of which is to monitor the ice by remote sensing, researchers didn’t have any reason to be alarmed the area where the Southern Antarctic Peninsula is located. It showed no indications of any changes until 2009. However, not long after, several glaciers along a span of a wide area with the size of about 750 kilometer or 460 miles in length, began thawing and pouring water into the ocean at a regular volume of of 60 cubic km, or approximately 55 trillion liters of water, annually.
“It appears that sometime around 2009, the ice-shelf thinning and the subsurface melting of the glaciers passed a critical threshold that triggered the sudden ice loss,” Bert Wouters, who led the study that appeared in Science this week and is with the Bristol Glaciology Centre at the University of Bristol, said.
This makes the area the next largest source to sea level increase in Antarctica. “To date, the glaciers added roughly 300 cubic km of water to the ocean,” Wouters said. “That’s the equivalent of the volume of nearly 350,000 Empire State Buildings combined.”
The ice loss in the area is so huge, it causes minute shifts in the gravity field of the planet, which is detectable by another satellite set up, the Gravity Recovery and Climate Experiment (GRACE).
“The fact that so many glaciers in such a large region suddenly started to lose ice came as a surprise to us,” Wouters said. “It shows a very fast response of the ice sheet: in just a few years the dynamic regime completely shifted.”
Records from an Antarctic model reveals that the abrupt shift cannot be determined basing it by the changes in snowfall and temperature. Rather, the team attributes the quick ice loss to the oceans increasing temperature in recent years due increase in fossil fuel carbon emissions.
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