Friday, May 27, 2005
On The Rocks
Report: Antarctic Ice Sheet Thickening
Fri May 20, 8:25 PM ET
TUCSON, Ariz. - Part of the Antarctic ice sheet is getting thicker, slightly slowing rising ocean levels, according to a new report co-authored by a University of Arizona graduate student.
In the past 10 years, the warmer temperatures over the eastern part of the Antarctic ice sheet have allowed that air to gather more moisture. Snow has been falling and causing part of the ice sheet to thicken � slowing the rise of the sea level by a tiny amount.
"The interior of the east Antarctic ice sheet is the only large terrestrial ice body that is likely gaining mass rather than losing it," said Curt Davis, an engineering professor at the University of Missouri-Columbia, who co-authored the report.
"This study suggests that the interior areas of ice sheets also can play an important role. In particular, the east Antarctic ice sheet is the largest in the world and contains enough mass to change sea level by more than 50 meters."
Fifty meters is about 165 feet, more than enough to drown the world's islands and coasts, many of which are just a few meters above the current sea level.
The researchers used satellite images and elevation changes they saw in cored ice samples. They said their work pertains only to the interior, eastern part of the Antarctic ice sheet. Other parts of the sheet may be contributing to rises in sea level, not mitigating them.
UA graduate student Markus Frey said that with results that only document what's happened in the past 10 years, it's impossible to tell whether the trends will continue, and whether they've been caused by natural climate variation or human-caused global warming.
The rise in sea level that would accompany melting of the polar ice sheets is widely regarded as one of the most serious potential consequences of global warming.
During the past century, warmer temperatures have caused melting of the Greenland and Antarctic ice sheets and mountain glaciers, which has translated into a rise in the oceans. The trend is expected to continue. The effects have the potential to impact coastal communities all over the globe.
"At first it will affect islands in the Southern Pacific and coastal areas," Frey said. "It also means the frequency of floods will increase. The Netherlands, Florida, places below sea level can get flooded more often. Storm tides would reach farther inland. It depends where you are. It's already happening."