Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Greenland will be far greater contributor to sea rise than expected

19.05.2014

Major UCI-NASA work reveals long, deep valleys connecting ice cap to the ocean

Greenland's icy reaches are far more vulnerable to warm ocean waters from climate change than had been thought, according to new research by UC Irvine and NASA glaciologists. The work, published today in Nature Geoscience, shows previously uncharted deep valleys stretching for dozens of miles under the Greenland Ice Sheet.

The bedrock canyons sit well below sea level, meaning that as subtropical Atlantic waters hit the fronts of hundreds of glaciers, those edges will erode much further than had been assumed and release far greater amounts of water.

Ice melt from the subcontinent has already accelerated as warmer marine currents have migrated north, but older models predicted that once higher ground was reached in a few years, the ocean-induced melting would halt. Greenland's frozen mass would stop shrinking, and its effect on higher sea waters would be curtailed.

"That turns out to be incorrect. The glaciers of Greenland are likely to retreat faster and farther inland than anticipated – and for much longer – according to this very different topography we've discovered beneath the ice," said lead author Mathieu Morlighem, a UCI associate project scientist. "This has major implications, because the glacier melt will contribute much more to rising seas around the globe."

To obtain the results, Morlighem developed a breakthrough method that for the first time offers a comprehensive view of Greenland's entire periphery. It's nearly impossible to accurately survey at ground level the subcontinent's rugged, rocky subsurface, which descends as much as 3 miles beneath the thick ice cap.

Since the 1970s, limited ice thickness data has been collected via radar pinging of the boundary between the ice and the bedrock. Along the coastline, though, rough surface ice and pockets of water cluttered the radar sounding, so large swaths of the bed remained invisible.

Measurements of Greenland's topography have tripled since 2009, thanks to NASA Operation IceBridge flights. But Morlighem quickly realized that while that data provided a fuller picture than had the earlier radar readings, there were still major gaps between the flight lines.

To reveal the full subterranean landscape, he designed a novel "mass conservation algorithm" that combined the previous ice thickness measurements with information on the velocity and direction of its movement and estimates of snowfall and surface melt.

The difference was spectacular. What appeared to be shallow glaciers at the very edges of Greenland are actually long, deep fingers stretching more than 100 kilometers (almost 65 miles) inland.

"We anticipate that these results will have a profound and transforming impact on computer models of ice sheet evolution in Greenland in a warming climate," the researchers conclude.

"Operation IceBridge vastly improved our knowledge of bed topography beneath the Greenland Ice Sheet," said co-author Eric Rignot of UC Irvine and NASA's Jet Propulsion Laboratory. "This new study takes a quantum leap at filling the remaining, critical data gaps on the map."

###

Other co-authors are Jeremie Mouginot of UC Irvine and Helene Seroussi and Eric Larour of JPL. Funding was provided by NASA.

The team also reported stark new findings last week on accelerated glacial melt in West Antarctica. Together, the papers "suggest that the globe's ice sheets will contribute far more to sea level rise than current projections show," Rignot said.

About the University of California, Irvine: Located in coastal Orange County, near a thriving employment hub in one of the nation's safest cities, UC Irvine was founded in 1965. One of only 62 members of the Association of American Universities, it's ranked first among U.S. universities under 50 years old by the London-based Times Higher Education. The campus has produced three Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Michael Drake since 2005, UC Irvine has more than 28,000 students and offers 192 degree programs. It's Orange County's second-largest employer, contributing $4.3 billion annually to the local economy.

Media access: UC Irvine maintains an online directory of faculty available as experts to the media at today.uci.edu/resources/experts.php. Radio programs/stations may, for a fee, use an on-campus ISDN line to interview UC Irvine faculty and experts, subject to availability and university approval. For more UC Irvine news, visit news.uci.edu. Additional resources for journalists may be found at communications.uci.edu/for-journalists.

Janet Wilson | Eurek Alert!

Further reports about: Climate change Greenland Greenland ice sheet IceBridge NASA Orange glaciers topography

More articles from Earth Sciences:

nachricht Past and present sea levels in the Chesapeake Bay Region, USA
29.07.2015 | Geological Society of America

nachricht “Carbon sink” detected underneath world’s deserts
29.07.2015 | American Geophysical Union

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Superfast fluorescence sets new speed record

Plasmonic device has speed and efficiency to serve optical computers

Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.

Im Focus: Unlocking the rice immune system

Joint BioEnergy Institute study identifies bacterial protein that is key to protecting rice against bacterial blight

A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team...

Im Focus: Smarter window materials can control light and energy

Researchers in the Cockrell School of Engineering at The University of Texas at Austin are one step closer to delivering smart windows with a new level of energy efficiency, engineering materials that allow windows to reveal light without transferring heat and, conversely, to block light while allowing heat transmission, as described in two new research papers.

By allowing indoor occupants to more precisely control the energy and sunlight passing through a window, the new materials could significantly reduce costs for...

Im Focus: Simulations lead to design of near-frictionless material

Argonne scientists used Mira to identify and improve a new mechanism for eliminating friction, which fed into the development of a hybrid material that exhibited superlubricity at the macroscale for the first time. Argonne Leadership Computing Facility (ALCF) researchers helped enable the groundbreaking simulations by overcoming a performance bottleneck that doubled the speed of the team's code.

While reviewing the simulation results of a promising new lubricant material, Argonne researcher Sanket Deshmukh stumbled upon a phenomenon that had never been...

Im Focus: NASA satellite camera provides 'EPIC' view of Earth

A NASA camera on the Deep Space Climate Observatory (DSCOVR) satellite has returned its first view of the entire sunlit side of Earth from one million miles away.

The color images of Earth from NASA's Earth Polychromatic Imaging Camera (EPIC) are generated by combining three separate images to create a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Euro Bio-inspired - International Conference and Exhibition on Bio-inspired Materials

23.07.2015 | Event News

Clash of Realities – International Conference on the Art, Technology and Theory of Digital Games

10.07.2015 | Event News

World Conference on Regenerative Medicine in Leipzig: Last chance to submit abstracts until 2 July

25.06.2015 | Event News

 
Latest News

A New Litmus Test for Chaos?

29.07.2015 | Physics and Astronomy

New Computer Model Could Explain how Simple Molecules Took First Step Toward Life

29.07.2015 | Life Sciences

New ERC calls published under Horizon 2020

29.07.2015 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>