Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Greenland Ice Cap May Be Melting At Triple Speed
08-12-2006, 09:24 PM,
#1
Greenland Ice Cap May Be Melting At Triple Speed
Quote:Greenland ice cap may be melting at triple speed
19:00 10 August 2006
NewScientist.com news service
Kelly Young


The world's second largest ice cap may be melting three times faster than indicated by previous measurements, according to newly released gravity data collected by satellites.

The Greenland Ice Sheet shrank at a rate of about 239 cubic kilometres per year from April 2002 to November 2005, a team from the University of Texas at Austin, US, found. In the last 18 months of the measurements, ice melting has appeared to accelerate, particularly in southeastern Greenland.

"This is a good study which confirms that indeed the Greenland ice sheet is losing a large amount of mass and that the mass loss is increasing with time," says Eric Rignot, from NASA's Jet Propulsion Laboratory in Pasadena, California, US, who led a separate study that reached a similar conclusion earlier in 2006 (See Greenland's glaciers are speeding to the ocean). His team used satellites to measure the velocity of glacier movement and calculate net ice loss.

Yet another technique, which uses a laser to measure the altitude of the surface, determined that the ice sheet was losing about 80 cubic kilometres of ice annually between 1997 and 2003. The newer measurements suggest the ice loss is three times that.

"Acceleration of ice mass loss over Greenland, if confirmed, would be consistent with proposed increased global warming in recent years, and would indicate additional polar ice sheet contributions to global sea level rise," write the University of Texas researchers in the journal Science.
Identical twins

The satellites that provided the new data are results the Gravity Recovery and Climate Experiment (GRACE) pair. These identical US and German satellites fly 220 kilometres from one another. They use a microwave ranging system and Global Positioning System to measure precisely the distance between one another. Tiny changes in that distance reflect changes in the Earth's gravity field, which in turn is a measure of the density of part of the Earth.

"The gravity data are spectacular in providing precise information about what is happening to the ice sheets," says NASA climatologist James Hansen, director of the Goddard Institute for Space Studies in New York, US. "They provide the net effect of mass change, due to both melting and snowfall changes. It confirms our expectation that the warming climate will cause Greenland ice to shrink."

Based on the glaciology of the region, Rignot says he does not think that the north-eastern part of Greenland's ice cap has lost as much ice as the Texas team suggests - 74 cubic kilometres annually.

Other factors could account for the discrepancy, acknowledges Clark Wilson, one of the University of Texas team. For instance, scientists do not fully understand the ocean tides in the Arctic Ocean, and there are not a lot of weather stations to monitor air pressure there. GRACE only measures changes in gravity due to changing mass - it cannot tell if that results from changes in air, water, rock or ice.

So to find changes due to ice loss alone, the researchers have to subtract the estimated contribution of water and air. If that is not well known, it results in higher uncertainties in the interpretation.

"We're hoping as time goes on, we'll have improved tide models, improved atmospheric pressure estimates and also better ways to use the GRACE data themselves," Wilson told New Scientist.
Thwarted plans

The Greenland Ice Sheet holds about 2.85 million cubic kilometres of ice - 10% of the world's ice mass. If it all melted, it would raise the average sea level about 6.5 metres.

This is not GRACE's first measurement of an ice sheet. Another team at the University of Colorado, Boulder, US, similarly used the GRACE system to show that the Antarctic ice sheet was losing about 152 cubic kilometres annually from 2002 to 2005 (See Gravity reveals shrinking Antarctic ice).

"We should be making plans for the next generation of gravity satellites, but with the cutback in NASA funding for Earth science, this is not happening," says Hansen, who earlier in 2006 accused officials at NASA headquarters of trying to stop him from speaking out on greenhouse gas emissions (See Top climatologist accuses US of trying to gag him).

Journal reference:Science (DOI:10.1126/science.1129007)

http://www.newscientist.com/article/dn9717...iple-speed.html
[Image: absurditiesvoltaire300oh0.gif]
------------------
&I've come to the conclusion, after having spent many years in politics, is that our presidential elections turn out to be more of a charade than anything else, and I think that is true today. It is a charade,& - Ron Paul, Sept 2008.
------------------
We're in a lot of trouble, watch this - http://www.youtube.com/v/3L3QVn4JyYA
------------------
[Image: guns250x200dw9.jpg]
[Image: armiw4.gif]
------------------
You cannot tax someone's labor because that is slavery
- Ed Brown, June 18 2007
------------------
The world's &freeest& country has the highest number in prison.
- arundhati roy
------------------
The crisis of modern democracy is a profound one. Free elections, a free press and an independent judiciary mean little when the free market has reduced them to commodities available on sale to the highest bidder.
- arundhati roy
------------------
The era of manufacturing consent has given way to the era of manufacturing news. Soon media newsrooms will drop the pretense, and start hiring theater directors instead of journalists.
- arundhati roy
------------------
The structure of capitalism is flawed. The motor that powers it cannot but vastly increase the disparity between the poor and the rich globally and within countries as well. Parecon is a brave argument for replacing that flawed machine and offers a much needed -- more equitable, democratic, participatory -- alternative economic vision.
- arundhati roy
------------------
[The choice between John Kerry and George Bush] is not a real choice. It's an apparent choice. Like choosing a brand of detergent. Whether you buy Ivory Snow or Tide, they're both owned by Proctor & Gamble.
- arundhati roy
------------------
No government's condemnation of terrorism is credible if it cannot show itself to be open to change by nonviolent dissent
- arundhati roy
[Image: sigterrorgj3.jpg]
------------------
Dr. Hermann Oberth who pioneered rocket design for the German Reich during World War II and later advanced rocket technology for the American manned space launches, cryptically stated: "We cannot take the credit for our record advancement in certain scientific fields alone; we have been helped."

When asked by whom, he replied: "The people of other worlds."
Reply
08-22-2006, 08:33 PM,
#2
Greenland Ice Cap May Be Melting At Triple Speed
The way Greenland's ice cap melting keeps speeding up how come it's still there!? It should have dissappeared last week sometime!

(BTW: Just because I'm a global waming denier doesn't mean that I think we humans are relieved of our responsibility to stop pollution and protect the environment. Humans are doing terrible damage to our home planet and we should stop!)
&I am merely offering a way out for your client. Anyone with a record of such incessant murder and robbery would be glad to cop an insanity plea. Do you insist that your client was in full possession of its reason at Wounded Knee, Hiroshima or Dresden?&
Reply
08-23-2006, 04:10 AM,
#3
Greenland Ice Cap May Be Melting At Triple Speed
I have been begining to formulate an idea that this global warming/climate change is "IT" the big one. Instead of some biological or nuclear catastrophy for the big takeover, the elite will simply snap up resources such as water and land in cooler climates which will become increasingly dear as the climate changes and also urge and speed up the changes... still developing, a lot of sniffing around disclosure statements.
Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  Why the Greenland and Antarctic Ice Sheets are Not Collapsing icosaface 3 1,288 12-12-2010, 06:54 PM
Last Post: Doc Quack
  Greenland ice sheet --- 20 6,372 04-20-2010, 09:46 AM
Last Post: ---
  Antarctic ice is growing, not melting away hilly7 3 1,107 04-20-2009, 04:38 PM
Last Post: ---
  MMR Triple Vaccine cultured from the remains of aborted babies plasticfan 9 2,400 03-15-2008, 09:04 AM
Last Post: faust
  Greenland Sled Dogs are abused in an unthinkable manner Solve et Coagula 0 768 01-15-2008, 08:59 PM
Last Post: Solve et Coagula

Forum Jump:


Users browsing this thread: 1 Guest(s)