Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Lasers from space show thinning of Greenland and Antarctic ice sheets

25.09.2009
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 glaciers 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 coastline – 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 sea level 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.

Issued by the British Antarctic Survey Press Office

Athena Dinar, Tel: +44 (0)1223 221 414; mobile: 07740 822229 email: amdi@bas.ac.uk;

Linda Capper, Tel: ++44 (0) 1223 221448; mobile: 07714 233744 email: lmca@bas.ac.uk

Authors:
Dr Hamish Pritchard, Tel: ++44 (0) 1223 221293; email: hprit@bas.ac.uk
Professor David Vaughan, Tel: ++44 (0) 1223 221643; email: dgv@bas.ac.uk
Notes for Editors:
Stunning broadcast-quality footage and stills of Antarctica, as well as location maps are available from the BAS Press Office as above.

Extensive dynamic thinning on the margins of the Greenland and Antarctic ice 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).

The team used data from NASA's high-resolution ICESat (Ice, Cloud and Land Elevation Satellite). Launched in January 2003, ICESat was sent into a polar orbit to examine changes in the world's ice and land masses -- particularly ice mass balance -- as well cloud and aerosol height. The satellite's lasers have measured the surface elevation of the Earth's ice sheets with unprecedented accuracy. The satellite's repeated passes over both poles create a wide net of coverage, and contribute to a long-term time series of topographic changes.

For the first time scientists can see the elevation change over the whole of the Antarctic Peninsula, and that glaciers in this area have the highest rates of thinning recorded in Antarctica or Greenland.

A glacier – is a 'river of ice' that is fed by the accumulation of snow. Glaciers drain ice from the mountains to lower levels, where the ice either melts, breaks away into the sea as icebergs, or feeds into an ice shelf.

Ice sheet – is the huge mass of ice, up to 4 km thick that covers bedrock in Antarctica or Greenland. It flows from the centre of the continent towards the coast where it feeds ice shelves.

Ice shelf – is the floating extension of the grounded ice sheet. It is composed of freshwater ice that originally fell as snow, either in situ or inland and brought to the ice shelf by glaciers. As they are already floating, any disintegration will have no impact on sea level. Sea level will rise only if the ice held back by the ice shelf flows more quickly onto the sea.

The Cambridge-based British Antarctic Survey (BAS) is a world leader in research into global environmental issues. With an annual budget of around £45 million, five Antarctic Research Stations, two Royal Research Ships and five aircraft, BAS undertakes an interdisciplinary research programme and plays an active and influential role in Antarctic affairs. BAS has joint research projects with over 40 UK universities and has more than 120 national and international collaborations. It is a component of the Natural Environment Research Council. More information about the work of the Survey can be found at: www.antarctica.ac.uk

* 43 million satellite measurements of the Antarctic and 7 million of Greenland over a 5 year period (2003-2007)

Athena Dinar | EurekAlert!
Further information:
http://www.bas.ac.uk

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Gold shines through properties of nano biosensors

17.08.2017 | Physics and Astronomy

Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter

17.08.2017 | Earth Sciences

Mars 2020 mission to use smart methods to seek signs of past life

17.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>