Lasers from space show thinning of Greenland and Antarctic ice sheets

September 23, 2009

The most comprehensive picture of the rapidly thinning glaciers along the coastline of both the Antarctic and Greenland ice sheets has been created using satellite lasers. The findings are an important step forward in the quest to make more accurate predictions for future sea level rise.

Reporting this week in the journal Nature researchers from British Antarctic Survey and the University of Bristol describe how analysis of millions of NASA satellite measurements* from both of these vast ice sheets shows that the most profound ice loss is a result of speeding up where they flow into the sea.

The authors conclude that this 'dynamic thinning' of glaciers now reaches all latitudes in Greenland, has intensified on key Antarctic coastlines, is penetrating far into the ice sheets' interior and is spreading as ice shelves thin by ocean-driven melt. Ice shelf collapse has triggered particularly strong thinning that has endured for decades.

Lead author Dr Hamish Pritchard from British Antarctic Survey (BAS) says, "We were surprised to see such a strong pattern of thinning glaciers across such large areas of - it's widespread and in some cases thinning extends hundreds of kilometres inland. We think that warm ocean currents reaching the coast and melting the glacier front is the most likely cause of faster glacier flow. This kind of ice loss is so poorly understood that it remains the most unpredictable part of future rise."

The scientists compared the rates of change in elevation of both fast-flowing and slow-flowing ice. In Greenland for example they studied 111 fast-moving glaciers and found 81 thinning at rates twice that of slow-flowing ice at the same altitude.They found that ice loss from many glaciers in both Antarctica and Greenland is greater than the rate of snowfall further inland.

In Antarctica some of the fastest thinning glaciers are in West Antarctica (Amundsen Sea Embayment) where Pine Island Glacier and neighbouring Smith and Thwaites Glacier are thinning by up to 9 metres per year.

More information: Extensive dynamic thinning on the margins of the Greenland and Antarctic sheets by Hamish D. Pritchard, Robert J. Arthern, David G. Vaughan & Laura A. Edwards is published online this week in the journal Nature (Advanced Online Publication).

Source: British (news : web)

Explore further: West Antarctic Glaciers Are Increasinly Thinning

Related Stories

West Antarctic Glaciers Are Increasinly Thinning

September 25, 2004

Glaciers in West Antarctica are shrinking at a rate substantially higher than observed in the 1990s. They are losing 60 percent more ice into the Amundsen Sea than they accumulate from inland snowfall. The study was conducted ...

Warming oceans threaten Antarctic glaciers

March 15, 2007

Scientists have identified four Antarctic glaciers that pose a threat to future sea levels using satellite observations, according to a study published in the journal Science.

Recommended for you

Playing 'tag' with pollution lets scientists see who's 'it'

July 29, 2015

Using a climate model that can tag sources of soot from different global regions and can track where it lands on the Tibetan Plateau, researchers have determined which areas around the plateau contribute the most soot—and ...

'Carbon sink' detected underneath world's deserts

July 28, 2015

The world's deserts may be storing some of the climate-changing carbon dioxide emitted by human activities, a new study suggests. Massive aquifers underneath deserts could hold more carbon than all the plants on land, according ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.