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




ICE WORLD
Himalayan meltdown not so fast after all: study
by Staff Writers
Paris, France (AFP) Feb 9, 2012


Himalayan glaciers and ice caps that supply water to more than a billion people in Asia are losing mass up to 10 times less quickly than once feared, reports a study published Thursday.

Based on an improved analysis of satellite data from 2003 to 2010, the findings offer a reprieve for a region already feeling the impacts of global warming.

But they do not mean that the threat of disruptive change has disappeared, the researchers warned.

"The good news is that the glaciers are not losing mass as fast as we thought," said Tad Pfeffer, a professor at the University of Colorado's Institute of Arctic and Alpine Research and a co-author of the study.

"The bad news is that they are still losing a lot of water. There is still definitely a serious problem for the Himalayas."

Much of that loss, it turns out, is taking place in the huge plains immediately south of the towering mountain range, where pumping from wells is draining ancient aquifers far faster than precipitation can replenish them.

Earlier estimates -- also based on satellite data -- mistakenly attributed much of the draining of these water tables to glacier melt-off, Pfeffer said in a phone interview.

Other calculations now thought to be off the mark were based on scaled-up extrapolations from lower-elevation glaciers that were more accessible to observation, but also more subject to warming trends.

"Many of the high glaciers would still be too cold to lose mass even in the presence of atmospheric warming," said co-author John Wahr, a physicist at the University of Colorado.

The study, published in Nature, provides what may be the most accurate global estimate of how much mass Earth's frozen regions -- glaciers, ice caps and the continent-sized icesheets sitting atop Greenland and Antarctica -- have shed over the last decade.

From 2003 through 2010, they collectively lost about 4,200 cubic kilometres (1,000 cubic miles), enough to raise sea levels by 12 millimetres (a half-inch) over that eight year period, the study found.

Most of that increase came from the Greenland and West Antarctica, while only 3.2 mm (0.125 inches) of the total can be attributed to the world's melting glaciers and ice caps.

"For high-mountain Asia, we are reporting loss of only four gigatonnes (Gt), or four cubic kilometres, annually," said Pfeffer. "Other studies have reported loss as high as 50 Gt per year. There's a big difference."

For the icesheets, however, the new estimates of ice mass loss over the last decade are roughly in line with other measurements based on different methods, the researchers said.

The second major driver of rising oceans is thermal expansion -- water taking up more space as the atmosphere heats up.

Satellite data used in the study, published in Nature, was taken from the Gravity Recovery and Climate Experiment, or GRACE, a joint NASA-German effort to measure changes in the planet's gravity field.

Two GRACE satellites launched in 2002 whip around Earth in tandem 16 times a day at an altitude of about 480 kilometres (300 miles), sensing subtle variations in gravitational pull caused by shifts in mass in ice sheets, oceans and water stored in the soil and in underground aquifers.

The new data will help scientists refine predictions about how quickly sea levels will rise, and by how much.

Current estimates vary between about half-a-metre and a metre by century's end.

"A better estimate of past behaviour, such as that obtained [in the new study], will therefore result in better estimates of future behaviour," Jonathan Bamber, a professor at the University of Bristol, noted in a commentary, also in Nature.

.


Related Links
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
First plants caused ice ages
Exeter, UK (SPX) Feb 08, 2012
New research reveals how the arrival of the first plants 470 million years ago triggered a series of ice ages. Led by the Universities of Exeter and Oxford, the study is published in Nature Geoscience. The team set out to identify the effects that the first land plants had on the climate during the Ordovician Period, which ended 444 million years ago. During this period the climate gradual ... read more


ICE WORLD
China publishes high-resolution full moon map

Manned Moon Shot Possible by 2020

NASA Mission Returns First Video From Lunar Far Side

A Moon Colony by 2020

ICE WORLD
NASA budget will axe Mars deal with Europe: scientists

Mars radar finds possible ocean sediments

Mars Express radar gives strong evidence for former Mars ocean

Surface of Mars an unlikely place for life after 600 million year drought

ICE WORLD
NASA PIT Crews Essential to Commercial Space Endeavor

Jacob Bleacher Gives Free RATS Talk at Library of Congress

NASA Calls for New Commercial Crew Proposals

Precision space maneuvers

ICE WORLD
China's new rockets expected to debut within five years

China announces new launch rockets

China's satellite navigation sector annual output predicted to reach 35 bln USD in 2015

China plans to launch 21 rockets, 30 satellites this year

ICE WORLD
Astronauts seen and heard

Next manned ISS mission to launch May 15: Russia

Capsule failure delays ISS crew mission

Russia to postpone next manned space launch: official

ICE WORLD
SpaceX to Launch AsiaSat 6 and AsiaSat 8 in 2014

Mobile Launcher Tests Confirm Designs

Iran to launch new generation of satellites

ULA Completes Critical Milestones Toward Certifying Atlas V for Human Spaceflight

ICE WORLD
Elements of ExoPlanets

New super-Earth detected within the habitable zone of a nearby star

Russia to Start Own Search for Extrasolar Planets

Planets Circling Around Twin Suns

ICE WORLD
Ailing Kodak shutters its camera operations

Redu Space Services To Build EDRS Mission Operation Centre

No more Brownie: Kodak gives up making cameras

Crystalline materials enable high-speed electronic function in optical fibers




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