Featured Research

from universities, journals, and other organizations

Scientists Detect Thickening Of West Antarctic Ice Sheet

Date:
January 30, 2002
Source:
University Of California Santa Cruz
Summary:
The stability of the West Antarctic ice sheet has long been a concern because of the potentially catastrophic rise in sea level that would result from its collapse. Researchers at UCSC and NASA now report that, contrary to previous studies, at least one part of the ice sheet is actually growing rather than shrinking.

The stability of the West Antarctic ice sheet has long been a concern because of the potentially catastrophic rise in sea level that would result from its collapse. Researchers at UCSC and NASA now report that, contrary to previous studies, at least one part of the ice sheet is actually growing rather than shrinking.

Assistant professor of Earth sciences Slawek Tulaczyk and Ian Joughin of NASA's Jet Propulsion Laboratory used satellite radar images to map the flow of ice in the ice sheet and estimate how its mass is changing. They reported their findings in the January 18 issue of the journal Science.

"The West Antarctic ice sheet has been retreating for several thousand years, so to look now and see that it is growing is staggering to me," Tulaczyk said. "Within the past 200 years, the ice sheet seems to have switched fairly rapidly from a negative mass balance to a positive mass balance."

Antarctica's huge ice sheets are fed by snow falling in the interior of the continent. The ice gradually flows out toward the edges. The West Antarctic ice sheet is considered less stable than the larger East Antarctic ice sheet because much of it rests on land that is below sea level, and parts of it, called ice shelves, are floating on the sea.

A positive mass balance means that more ice is accumulating than is leaving the ice sheet. The reason, according to Tulaczyk and Joughin, is that major ice streams have slowed or stopped moving altogether. Ice streams are fast-moving currents of ice within the ice sheet that carry large volumes of ice out onto the floating ice shelves.

Earlier work by Tulaczyk may explain why the ice streams are slowing down. The ice streams slide over a bed of sediment saturated with liquid water, but an ice stream will grind to a halt if its bed becomes cold enough for the water to freeze. Tulaczyk showed that thinning of the ice sheet allows more heat to escape from the bed, eventually leading to freezing conditions.

The ice sheet has been retreating and thinning since the end of the last ice age more than 10,000 years ago. The changes now being detected by Tulaczyk and Joughin may signal the end of this process.

"It is either some kind of short-term fluctuation that we don't quite understand, or it's a trend and we just happened to come along at the right time to observe an event that only happens once in 10,000 years," Tulaczyk said. "To think that it just happens to be doing this now when we can observe it leaves me feeling a little queasy," he added.

One reason for that queasiness is that no one is quite sure what the long-term implications of these changes may be. Tulaczyk noted that if the ice streams continue to slow and stop, the ice shelf that covers the Ross Sea is likely to break up. The removal of the lid of ice that currently covers the Ross Sea could have significant effects on global ocean circulation and the global climate, he said.


Story Source:

The above story is based on materials provided by University Of California Santa Cruz. Note: Materials may be edited for content and length.


Cite This Page:

University Of California Santa Cruz. "Scientists Detect Thickening Of West Antarctic Ice Sheet." ScienceDaily. ScienceDaily, 30 January 2002. <www.sciencedaily.com/releases/2002/01/020130074839.htm>.
University Of California Santa Cruz. (2002, January 30). Scientists Detect Thickening Of West Antarctic Ice Sheet. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2002/01/020130074839.htm
University Of California Santa Cruz. "Scientists Detect Thickening Of West Antarctic Ice Sheet." ScienceDaily. www.sciencedaily.com/releases/2002/01/020130074839.htm (accessed July 31, 2014).

Share This




More Earth & Climate News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Florida Panther Rebound Upsets Ranchers

Florida Panther Rebound Upsets Ranchers

AP (July 31, 2014) With Florida's panther population rebounding, some ranchers complain the protected predators are once again killing their calves. (July 31) Video provided by AP
Powered by NewsLook.com
Big Waves In Arctic Ocean Threaten Polar Ice

Big Waves In Arctic Ocean Threaten Polar Ice

Newsy (July 30, 2014) Big waves in parts of the Arctic Ocean are unprecedented, mainly because they used to be covered in ice. Video provided by Newsy
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins