Hundreds of Antarctic Peninsula glaciers accelerating as climate warms
Hundreds of glaciers on the Antarctic Peninsula are flowing faster, further adding to sea level rise according to new research published this week in the Journal of Geophysical Research. Climate warming, that is already causing Antarctic Peninsula increased summer snow melt and ice shelf retreat, is the most likely cause.
Using radar images acquired by European ERS-1 and -2 satellites, scientists from British Antarctic Survey (BAS) tracked the flow rate of over 300 previously unstudied glaciers. They found a 12% increase in glacier speed from 1993 to 2003. These observations – that echo recent findings from coastal Greenland – indicate that the cause is melting of the lower glaciers, which flow directly into the sea. As they thin, the buoyancy of the ice can lift the glaciers off their rock beds, allowing them to slide faster.
In February this year, the United Nations Intergovernmental Panel on Climate Change (IPCC) reported that they could not provide an upper limit on the rate of sea-level rise from Antarctica in coming centuries because of a lack of understanding of the behaviour of the large ice sheets. These new results give scientists a clearer picture about the way that climate warming can affect glaciers both in the Arctic and Antarctic. Furthermore, they pave the way for more reliable projections of future sea level rise, and provide a better basis for policy decisions.
Lead author Dr Hamish Pritchard says,
“The Antarctic Peninsula has experienced some of the fastest warming on Earth, nearly 3°C over the last half-century. Eighty-seven percent of its glaciers have been retreating during this period and now we see these glaciers are also speeding up. It’s important that we use tools such as satellite technology that allow us to monitor changes in remote and inaccessible glaciers on a regional scale. Understanding what’s happening now gives us our best chance of predicting what’s likely to happen in the future.” ENDS
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Issued by the British Antarctic Survey Press Office.
Linda Capper – tel: ++44 1223 221448, mob: 07714 233744, email: [email protected]
Athena Dinar – tel: ++44 1223 221414, mob:07740 822229, email: [email protected]
Author contact: Hamish Pritchard. Tel 01223 221293 email: [email protected]
Notes for Editors:
The paper, “Widespread acceleration of tidewater glaciers on the Antarctic Peninsula ” by Hamish Pritchard and David Vaughan is published this week in the Journal of Geophysical Research.
Pictures: stills and broadcast-quality footage of the glaciers studied are available from the BAS Press Office
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 Antarctica ’s bedrock. 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 (like Larsen B) 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.
British Antarctic Survey is a world leader in research into global issues in an Antarctic context. It is the ’s national operator and is a component of the Natural Environment Research Council. It has an annual budget of around £40 million, runs nine research programmes and operates five research stations, two Royal Research Ships and five aircraft in and around Antarctica . More information about the work of the Survey can be found at: www.antarctica.ac.uk