Welcome to DU!
The truly grassroots left-of-center political community where regular people, not algorithms, drive the discussions and set the standards.
Join the community:
Create a free account
Support DU (and get rid of ads!):
Become a Star Member
Latest Breaking News
General Discussion
The DU Lounge
All Forums
Issue Forums
Culture Forums
Alliance Forums
Region Forums
Support Forums
Help & Search
Greenland and Antarctica 'have lost 4tn tonnes of ice' in 20 years
http://www.guardian.co.uk/environment/2012/nov/29/greenland-antarctica-4-trillion-tonnes-iceMore than 4tn tonnes of ice from Greenland and Antarctica has melted in the past 20 years and flowed into the oceans, pushing up sea levels, according to a study that provides the best measure to date of the effect climate change is having on the earth's biggest ice sheets.
The research involved dozens of scientists and 10 satellite missions and presents a disturbing picture of the impact of recent warming at the poles.
The scientists claim the study, published in the journal Science, ends a long-running debate over whether the vast ice sheet covering the Antarctic continent is losing or gaining mass. East Antarctica is gaining some ice, the satellite data shows, but west Antarctica and the Antarctic peninsula is losing twice as much, meaning overall the sheet is melting.
"The estimates are the most reliable to date, and end 20 years of uncertainty of ice mass changes in Antarctica and Greenland," said study leader, Andrew Shepherd, of Leeds University. "There have been 30 different estimates of the sea level rise contribution of Greenland and Antarctica, ranging from an annual 2mm rise to a 0.4mm fall.
13 replies
= new reply since forum marked as read
= new reply since forum marked as read
http://www.nasa.gov/topics/earth/features/20100108_Is_Antarctica_Melting.html
…
The Antarctic ice sheet. East Antarctica is much higher in elevation than West Antarctica.
…
Two-thirds of Antarctica is a high, cold desert. Known as East Antarctica, this section has an average altitude of about 2 kilometer (1.2 miles), higher than the American Colorado Plateau. There is a continent about the size of Australia underneath all this ice; the ice sheet sitting on top averages at a little over 2 kilometer (1.2 miles) thick. If all of this ice melted, it would raise global sea level by about 60 meter (197 feet). But little, if any, surface warming is occurring over East Antarctica. Radar and laser-based satellite data show a little mass loss at the edges of East Antarctica, which is being partly offset by accumulation of snow in the interior, although a very recent result from the NASA/German Aerospace Center's Gravity Recovery and Climate Experiment (Grace) suggests that since 2006 there has been more ice loss from East Antarctica than previously thought. Overall, not much is going on in East Antarctica -- yet.
A Frozen Hawaii
West Antarctica is very different. Instead of a single continent, it is a series of islands covered by ice -- think of it as a frozen Hawaii, with penguins. Because it's a group of islands, much of the West Antarctic Ice Sheet (WAIS, in the jargon) is actually sitting on the floor of the Southern Ocean, not on dry land. Parts of it are more than 1.7 kilometer (1 mile) below sea level. Pine Island is the largest of these islands and the largest ice stream in West Antarctica is called Pine Island Glacier. The WAIS, if it melted completely, would raise sea level by 5 to 7 meter (16 to 23 feet). And the Pine Island Glacier would contribute about 10 percent of that.
…
The Antarctic ice sheet. East Antarctica is much higher in elevation than West Antarctica.
…
Two-thirds of Antarctica is a high, cold desert. Known as East Antarctica, this section has an average altitude of about 2 kilometer (1.2 miles), higher than the American Colorado Plateau. There is a continent about the size of Australia underneath all this ice; the ice sheet sitting on top averages at a little over 2 kilometer (1.2 miles) thick. If all of this ice melted, it would raise global sea level by about 60 meter (197 feet). But little, if any, surface warming is occurring over East Antarctica. Radar and laser-based satellite data show a little mass loss at the edges of East Antarctica, which is being partly offset by accumulation of snow in the interior, although a very recent result from the NASA/German Aerospace Center's Gravity Recovery and Climate Experiment (Grace) suggests that since 2006 there has been more ice loss from East Antarctica than previously thought. Overall, not much is going on in East Antarctica -- yet.
A Frozen Hawaii
West Antarctica is very different. Instead of a single continent, it is a series of islands covered by ice -- think of it as a frozen Hawaii, with penguins. Because it's a group of islands, much of the West Antarctic Ice Sheet (WAIS, in the jargon) is actually sitting on the floor of the Southern Ocean, not on dry land. Parts of it are more than 1.7 kilometer (1 mile) below sea level. Pine Island is the largest of these islands and the largest ice stream in West Antarctica is called Pine Island Glacier. The WAIS, if it melted completely, would raise sea level by 5 to 7 meter (16 to 23 feet). And the Pine Island Glacier would contribute about 10 percent of that.
…
