Accelerated melting of two fast-moving outlet glaciers that drain
Antarctic ice into the Amundsen Sea Embayment is likely the result, in
part, of an increase in sea-surface temperatures in the tropical Pacific
Ocean, according to new University of Washington research.
Higher-than-normal sea-level pressure north of the Amundsen Sea sets
up westerly winds that push surface water away from the glaciers and
allow warmer deep water to rise to the surface under the edges of the
glaciers, said Eric Steig, a UW professor of Earth and space sciences.
"This part of Antarctica is affected by what's happening on the rest
of the planet, in particular the tropical Pacific," he said.
The research involves the Pine Island and Thwaites glaciers on the
West Antarctic Ice Sheet, two of the five largest glaciers in
Antarctica. Those two glaciers are important because they drain a large
portion of the ice sheet. As they melt from below, they also gain speed,
draining the ice sheet faster and contributing to sea level rise.
Eventually that could lead to global sea level rise of as much as 6
feet, though that would take hundreds to thousands of years, Steig said.
NASA scientists recently documented that a section of the Pine Island
Glacier the size of New York City had begun breaking off into a huge
iceberg. Steig noted that such an event is normal and scientists were
fortunate to be on hand to capture a video recording. Neither that event
nor the new UW findings clearly link thinning Antarctic ice to human
causes.
No comments:
Post a Comment