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




ICE WORLD
'Hidden Plumbing' Helps Slow Greenland Ice Flow
by Staff Writers
Leeds, UK (SPX) Jan 31, 2011


Summertime acceleration of ice flow has proved difficult for scientists to model, leading to uncertainties in projections of future sea level rise.

Hotter summers may not be as catastrophic for the Greenland ice sheet as previously feared and may actually slow down the flow of glaciers, according to new research.

A letter published in Nature explains how increased melting in warmer years causes the internal drainage system of the ice sheet to 'adapt' and accommodate more melt-water, without speeding up the flow of ice toward the oceans. The findings have important implications for future assessments of global sea level rise.

The Greenland ice sheet covers roughly 80% of the surface of the island and contains enough water to raise sea levels by 7 metres if it were to melt completely. Rising temperatures in the Arctic in recent years have caused the ice sheet to shrink, prompting fears that it may be close to a 'tipping point' of no return.

Some of the ice loss has been attributed to the speed-up of glaciers due to increased surface melting. Each summer, warmer temperatures cause ice at the surface of the sheet to melt. This water then runs down a series of channels to the base of the glacier where it acts as a lubricant, allowing the ice sheet to flow rapidly across the bedrock toward the sea.

Summertime acceleration of ice flow has proved difficult for scientists to model, leading to uncertainties in projections of future sea level rise.

"It had been thought that more surface melting would cause the ice sheet to speed up and retreat faster, but our study suggests that the opposite could in fact be true," said Professor Andrew Shepherd from the University of Leeds School of Earth and Environment, who led the study.

"If that's the case, increases in surface melting expected over the 21st century may have no affect on the rate of ice loss through flow. However, this doesn't mean that the ice sheet is safe from climate change, because the impact of ocean-driven melting remains uncertain."

The researchers used satellite observations of six landlocked glaciers in south-west Greenland, acquired by the European Space Agency, to study how ice flow develops in years of markedly different melting.

Although the initial speed-up of ice was similar in all years, slowdown occurred sooner in the warmest ones. The authors suggest that in these years the abundance of melt-water triggers an early switch in the plumbing at the base of the ice, causing a pressure drop that leads to reduced ice speeds.

This behaviour is similar to that of mountain glaciers, where the summertime speed-up of ice reduces once melt-water can drain efficiently.

.


Related Links
University of Leeds
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
Scientists Find That Debris On Certain Himalayan Glaciers May Prevent Melting
Santa Barbara CA (SPX) Jan 27, 2011
A new scientific study shows that debris coverage - pebbles, rocks, and debris from surrounding mountains - may be a missing link in the understanding of the decline of glaciers. Debris is distinct from soot and dust, according to the scientists. Melting of glaciers in the Himalayan Mountains affects water supplies for hundreds of millions of people living in South and Central Asia. Expert ... read more


ICE WORLD
NASA's New Lander Prototype Skates Through Integration And Testing

Draper Commits One Million Dollars To Next Giant Leap's Moon Lander

Lunar water may have come from comets - scientists

Moon Has Earth-Like Core

ICE WORLD
Rover Conducting Science At Crater Rim

New images of martian moon released

DLR Researchers Simulate The Martian Atmosphere

The Southern Hemisphere Of Phobos, Up Close

ICE WORLD
NanoSail-D Flies Free

Major exhibit of NASA material opens in Stockholm

Mumbai's washermen fear rise of the machines

Solar Sail Stunner

ICE WORLD
Slow progress in U.S.-China space efforts

China Builds Theme Park In Spaceport

Tiangong Space Station Plans Progessing

China-Made Satellite Keeps Remote Areas In Venezuela Connected

ICE WORLD
Intensive Preparations For ATV Freighter Launch To ISS

Russian Space Freighter Progress M-09M Docks With ISS

Crew Attaches Japanese Resupply Vehicle To ISS

Russian cargo ship sends supplies to space

ICE WORLD
Activities At Esrange Space Center 2011

Russia Plans To Build Carrier Rocket For Mars Missions

First Delta IV Heavy Launches From Vandenberg

Beaming Rockets Into Space

ICE WORLD
Inclined Orbits Prevail

Inclined Orbits Prevail In Exoplanetary Systems

Planet Affects A Star's Spin

Kepler Mission Discovers Its First Rocky Planet

ICE WORLD
Mobile 'apps' to be $58 billion market: study

Touchscreens Made Of Carbon

DigitalGlobe Collaborates With Satellite Sentinel Project To Keep Eye On Sudan

China's Lenovo, NEC form PC joint venture in Japan




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