Ice loss in Antarctica increased by 75 percent in the last 10 years due to a speed-up in the flow of its glaciers and is now nearly as great as that observed in Greenland, according to a new, comprehensive study by UC Irvine and NASA scientists.
In a first-of-its-kind study, an international team led by Eric Rignot, professor of Earth system science at UCI and a scientist with NASA’s Jet Propulsion Laboratory, Pasadena, Calif., estimated changes in Antarctica’s ice mass between 1996 and 2006 and mapped patterns of ice loss on a glacier-by-glacier basis. They detected a sharp jump in Antarctica’s ice loss, from enough ice to raise global sea level by 0.3 millimeters (.01 inches) a year in 1996, to 0.5 millimeters (.02 inches) a year in 2006.
Rignot said the losses, which were primarily concentrated in West Antarctica’s Pine Island Bay sector and the northern tip of the Antarctic Peninsula, are caused by ongoing and past acceleration of glaciers into the sea. This is mostly a result of warmer ocean waters, which bathe the buttressing floating sections of glaciers, causing them to thin or collapse. “Changes in Antarctic glacier flow are having a significant, if not dominant, impact on the mass balance of the Antarctic ice sheet,” he said.
To infer the ice sheet’s mass, the team measured ice flowing out of Antarctica’s drainage basins over 85 percent of its coastline. They used 15 years of satellite radar data from the European Earth Remote Sensing-1 and -2, Canada’s Radarsat-1 and Japan’s Advanced Land Observing satellites to reveal the pattern of ice sheet motion toward the sea. These results were compared with estimates of snowfall accumulation in Antarctica’s interior derived from a regional atmospheric climate model spanning the past quarter century.
The team found that the net loss of ice mass from Antarctica increased from 112 (plus or minus 91) gigatonnes a year in 1996 to 196 (plus or minus 92) gigatonnes a year in 2006. A gigatonne is one billion metric tons, or more than 2.2 trillion pounds. These new results are about 20 percent higher over a comparable time frame than those of a NASA study of Antarctic mass balance last March that used data from the NASA/German Aerospace Center Gravity Recovery and Climate Experiment. This is within the margin of error for both techniques, each of which has its strengths and limitations.
Rignot says the increased contribution of Antarctica to global sea level rise indicated by the study warrants closer monitoring.
“Our new results emphasize the vital importance of continuing to monitor Antarctica using a variety of remote sensing techniques to determine how this trend will continue and, in particular, of conducting more frequent and systematic surveys of changes in glacier flow using satellite radar interferometry,” Rignot said. “Large uncertainties remain in predicting Antarctica’s future contribution to sea level rise. Ice sheets are responding faster to climate warming than anticipated.”
Rignot said scientists are now observing these climate-driven changes over a significant fraction of the West Antarctic Ice Sheet, and the extent of the glacier ice losses is expected to keep rising in the years to come. “Even in East Antarctica, where we find ice mass to be in near balance, ice loss is detected in its potentially unstable marine sectors, warranting closer study,” he said.
Other organizations participating in the NASA-funded study are Centro de Estudios Cientificos, Valdivia, Chile; University of Bristol, United Kingdom; Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, The Netherlands; University of Missouri, Columbia, Mo.; and the Royal Netherlands Meteorological Institute, De Bilt, The Netherlands.
Article: Eric Rignot, Jonathan L. Bamber, Michiel R. van den Broeke, Curt Davis, Yonghong Li, Willem Jan van de Berg & Erik van Meijgaard, Recent Antarctic ice mass loss from radar interferometry and regional climate modelling, Nature Geoscience | doi:10.1038/ngeo102
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Sexual Fantasies: Threesomes Are Normal, Golden Showers Not So Much
- Ghost Light From Dead Galaxies - A Hubble Halloween
- Mediterranean Diet Linked To Better Kidney Health
- Greenpeace Says Its GMOs Are Better Than Science's GMOs, Still Hates Golden Rice
- US Wildlife Bans On GMOs And Neonics Lack Transparency And Scientific Rationale
- Coulrophobia: Are Clowns Scary? Ha Ha Aaaargh
- Game Theory: When Are Groups Social? Or Insufferable?
- "Twelve years in a major urban public school system, and I couldn't once bring myself to eat a school..."
- "Hardly a day goes by without some creative new take on the eternal Evil White Man meme. Without..."
- "There would be no controversy if it were all balloons and ponies stories like that. But I hope..."
- "Let's talk about this disaster: I lost a course at the university where I work and became ineligible..."
- "Partisan nastiness doesn't advance dialogue. We are all in this together. You asked for solutions..."
- Battle of Britain: NGOs and scientists clash over proposal to loosen EU GMO restrictions
- Genetically modified clean energy from bacteria
- Designer babies: You can screen for cystic fibrosis but intelligence is a ways off
- Science as profane: What superstition of 1752 and 2014 share in common
- What’s so “natural” about “natural crop breeding”?
- Worried you have cancer? Take a Google pill!
- Report examines health care challenges for pregnant women enrolled in covered California
- NYU research: Majority of high school seniors favor more liberal marijuana policies
- ESA Frontiers November preview
- Sexual fantasies: Are you normal?
- Synthetic lethality offers a new approach to kill tumor cells, explains Moffitt researcher