Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




ICE WORLD
Scientists Predict Faster Retreat for Antarctic Thwaites Glacier
by Staff Writers
New York NY (SPX) Oct 31, 2011


New seafloor topography off Antarctica's Thwaites Glaciers leads scientists to predict accelerated melting in the next 20 years. (Credit: Frank Nitsche, Lamont-Doherty)

The retreat of Antarctica's fast-flowing Thwaites Glacier is expected to speed up within 20 years, once the glacier detaches from an underwater ridge that is currently holding it back, says a new study in Geophysical Research Letters.

Washington DC (SPX) Oct 31, 2011 Thwaites Glacier, which drains into west Antarctica's Amundsen Sea, is being closely watched for its potential to raise global sea levels as the planet warms.

Neighboring glaciers in the Amundsen region are also thinning rapidly, including Pine Island Glacier and the much larger Getz Ice Shelf. The study is the latest to confirm the importance of seafloor topography in predicting how these glaciers will behave in the near future.

Scientists had previously identified a rock feature off west Antarctica that appeared to be slowing the glacier's slide into the sea. But this study is the first to connect it to a larger ridge, using geophysical data collected during flights over Thwaites Glacier in 2009 under NASA's Ice Bridge campaign.

The newly discovered ridge is 700 meters tall, with two peaks-one that currently anchors the glacier and another farther off shore that held the glacier in place between 55 and 150 years ago, according to the authors.

The goal of NASA's Ice Bridge campaign is to map the topography of vulnerable regions like this in Antarctica and Greenland by flying over the ice sheets with ice-penetrating radar and other instruments.

The discovery that Thwaites is losing its grip on a previously unknown ridge has helped scientists understand why the glacier seems to be moving faster than it used to.

As scientists map the contours of the seafloor in the Amundsen Sea region, they are forming a clearer picture of what the glaciers are doing. In 2009, researchers sent a robot submarine beneath Pine Island Glacier's floating ice tongue and discovered a ridge about half the size of the one off Thwaites Glacier.

Researchers estimate that Pine Island Glacier lifted off that ridge in the 1970s, allowing warm ocean currents to melt the glacier from below.

The glacier's ice shelf is now moving 50 percent faster than it was in the early 1990s, Lamont-Doherty oceanographer Stan Jacobs and colleagues detailed in a study in Nature Geoscience earlier this year. Pine Island Glacier is moving into the sea at the rate of 4 kilometers a year-four times faster than the fastest-moving section of Thwaites.

Lamont-Doherty geophysicist Robin Bell, study co-author, compares the ridge in front of Thwaites to a person standing in a doorway, holding back a crowd.

"Knowing the ridge is there lets us understand why the wide ice tongue that used to be in front of the glacier has broken up," she said.

"We can now predict when the last bit of floating ice will lift off the ridge. We expect more ice will come streaming out of the Thwaites Glacier when this happens."

"The bathymetry is the roadmap for how warm ocean water reaches the edges of the ice sheet," she added. "Ridges like this one and the one discovered in front of Pine Island Glacier stabilize ice sheets, but can also be a critical part of the destabilizing process."

.


Related Links
LDEO
NASA's Ice Bridge campaign
Beyond the Ice Age






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





ICE WORLD
NASA Continues Critical Survey of Antarctica's Changing Ice
Washington DC (SPX) Oct 14, 2011
Scientists with NASA's Operation IceBridge airborne research campaign began the mission's third year of surveys this week over the changing ice of Antarctica. Researchers are flying a suite of scientific instruments on two planes from a base of operations in Punta Arenas, Chile: a DC-8 operated by NASA and a Gulfstream V (G-V) operated by the National Science Foundation and the National Ce ... read more


ICE WORLD
Lunar Probe to search for water on Moon

Subtly Shaded Map of Moon Reveals Titanium Treasure Troves

NASA's Moon Twins Going Their Own Way

Titanium treasure found on Moon

ICE WORLD
Mars500 crew prepare to open the hatch

Opportunity Continues to Drive North

Opportunity Past 21 Miles of Driving! Will Spend Winter at Cape York

Scientists develope new way to determine when water was present on Mars and Earth

ICE WORLD
NASA's NEEMO Mission Ending Early Due To Hurricane Rina

Explorer 1 The First US Explorer

NASA evacuates astronauts from deep-sea training

Is Your Space Elevator Going Up

ICE WORLD
China to launch spacecraft on Tuesday: Xinhua

Sweet Dreams for Tiangong

German-Chinese SIMBOX ready for launch

Major moments of China's rocket launches

ICE WORLD
Russian space freighter leaves ISS

Station Crew Prepares For Progress Departure and New Arrivals

Russian Space Agency names next crew to ISS

ISS orbit readjusted by 3 km

ICE WORLD
Vega getting ready for exploitation

MSU satellite orbits the Earth after early morning launch

NASA Launches Multi-Talented Earth-Observing Satellite

The Arianespace launcher family comes together in French Guiana

ICE WORLD
Three New Planets and a Mystery Object Discovered Outside Our Solar System

Dwarf planet sized up accurately as it blocks light of faint star

Herschel Finds Oceans of Water in Disk of Nearby Star

UH Astronomer Finds Planet in the Process of Forming

ICE WORLD
Japan, India to accelerate joint rare earth development

Berkeley Lab Scientists Spy Molecular Maneuvers

S. Korean antitrust agency fines LCD makers $175m

Amazon, Netflix in deals with Disney-ABC




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement