Western Antartica’s immense
glaciers are melting fast and giving up ice to the sea at a rate that is
considered already past “the point of no return," according to recent
research work done by two different groups of scientists.
The resulting scenario is
compelling: an increase in the world sea levels of 4 feet or more in the next
centuries, according to findings announced Monday by scientists from the
University of Washington, the University of California-Irvine and the Jet
Propulsion Laboratory at NASA.
"It truly is a startlingly
disturbing situation," says Pennsylvania State University glaciologist
Sridhar Anandakrishnan, who was not associated with any of the research studies.
"This is a big part of West Antarctica, and it appears to have been pushed
violently over the edge."
The researchers claim the
glaciers are most certainly bound to be lost.
One study confirms that a river
of ice named Thwaites Glacier
is possibly starting to collapse and that complete collapse is likely to occur.
A second research illustrates
that six glaciers are giving up ice into the sea at an ever-increasing rate. At
that rate, there will be a 4-feet increase in the sea-level, states study
author Eric Rignot, a glaciologist at the University of California-Irvine, and
NASA's Jet Propulsion Laboratory.
"The ice retreat in that
area is inescapable," Rignot said at a briefing Monday, adding that the
glaciers have gone beyond “the point-of-no-return."
Rignot and his group utilized
data from satellites and aircraft to monitor changes in six West Antarctic
glaciers and the terrain beneath these massive ice floes. The data gathered
confirm that the glaciers are spreading out and decreasing in thickness and
volume. They are also moving faster from the continent's center toward the sea,
giving up more volumes of ice into the ocean than before and raising sea levels
as a result.
Simultaneously, the area of each
glacier protruding into the sea is being melted underwater by the surrounding warm
ocean water. This results in the vicious process of increased thinning and more
rapid flow, and the local terrain provides no barrier to the glaciers' retreat,
the researchers announce in the next issue of Geophysical Research Letters.
An article in this week's Science says the Thwaites
Glacier is predicted to collapse completely in 200 years. The paper, however,
does not specify the height of sea-level increase associated with Thwaites' disappearance.
No comments:
Post a Comment