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Study Sheds Light On Antarctic Ice Loss

03.02.2016
03.02.2016 17:12 Age: 2 yrs

In the first study of its kind, researchers were able to gauge how levels of ice covering the land have changed over hundreds of thousands of years

Click to enlarge. A researcher examines rocks in the West Antarctic landscape. Courtesy: Andy Hein and the University of Edinburgh

Click to enlarge. From the paper. a. Subglacial topography of Antarctica showing the field location in the Ellsworth Mountains and prominent geographical features within the Weddell Sea embayment. Courtesy: authors and Nature Communications

Click to enlarge. From the paper. b. Subglacial topography of the wider Ellsworth block and the present-day ice-surface contours (250 m) of the WAIS. White line indicates the grounding line; black lines are bed elevation contours at 0 m elevation (WGS84). The red line A-A’ shows the profile line used in c (below); it runs between the main dome of the WAIS and Hercules inlet. The rose diagram shows persistent katabatic winds from the south-southwest recorded at the Patriot Hills blue-ice aircraft runway over two months in the austral summer of 2008 Courtesy: authors and Nature Communications

Click to enlarge. From the paper. c. Profile of the bed and ice-sheet surface from the WAIS divide to Hercules Inlet, showing the deep troughs excavated below sea level surrounding the Patriot and Marble Hills. Courtesy: authors and Nature Communications

Click to enlarge. From the paper. d. Photograph showing dark-coloured erratics scattered across ice-scoured limestone bedrock of the Marble Hills. Wind-drift glaciers can be seen along the summit ridge to the right of Mt. Fordell Courtesy: authors and Nature Communications

 

From the University of Edinburgh

Loss of ice in Antarctica caused by a warming ocean could raise global sea levels by three metres, research suggests.

Scientists carrying out fieldwork in the region have assessed the landscape to determine how the West Antarctic ice sheet might respond to increasing global temperatures.

Landscape study

In the first study of its kind, researchers were able to gauge how levels of ice covering the land have changed over hundreds of thousands of years.

They did so by studying peaks protruding through ice in the Ellsworth Mountains, on the Atlantic flank of Antarctica.

The team assessed changes on slopes at various heights on the mountainside, which indicate levels previously reached by the ice sheet.

They also mapped the distribution of boulders on the mountainside, which were deposited by melting glaciers.

Chemical technology - known as exposure dating - showed how long rocks had been exposed to the atmosphere, and their age.

Ancient ice sheet

Their results indicate that during previous warm periods, a substantial amount of ice would have been lost from the West Antarctic ice sheet by ocean melting, but it would not have melted entirely.

This suggests that ice would have been lost from areas below sea level, but not on upland areas.

The study shows that parts of the West Antarctic ice sheet have existed continuously for at least 1.4 million years.

Collaborative study

The study, published in Nature Communications, was carried out by researchers at the University of Edinburgh with Northumbria University and the Scottish Universities Environmental Research Centre.

It was supported by the Natural Environment Research Council and the British Antarctic Survey.

Quotes

Abstract

Citation

Evidence for the stability of the West Antarctic Ice Sheet divide for 1.4 million years by Andrew S. Hein, John Woodward, Shasta M. Marrero, Stuart A. Dunning, Eric J. Steig, Stewart P. H. T. Freeman, Finlay M. Stuart, Kate Winter, Matthew J. Westoby and David E. Sugden published in Nature Communications, doi:10.1038/ncomms10325

Read the abstract and get the paper here.

Source

University of Edinburgh news release here.