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Video Clip
Thinning Ice Sheet [4:18]
Network
ABC Catalyst
Broadcast
29th April 2010
Summary
East Antarctica's ice sheet losing mass, 2010
Download Clip [15.88 MB]
Learning Area
Geography, Science
Strand/s
Science as a human endeavour, Science understanding, Earth and beyond
Year/s
5-12

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Description

This clip from ABC's 'Catalyst' program (2010) reveals scientific discoveries showing that the ice sheet in East Antarctica has been losing mass since 2006, reversing previous assumptions that it was growing in size. Reporter Mark Horstman looks at how satellite technology and aerial monitoring techniques are helping scientists determine the effects that changing temperatures are having on Antarctica's ice sheets. Scientists discuss how these changes are linked with predicted changes in the Earth's sea levels. Dr James Hansen (NASA) and glaciologist Neal Young and Dr Tas van Ommen, both of the Australian Antarctic Division, are featured in the clip.

Educational Value

This clip is a valuable resource for exploring how climate change is affecting ice sheets. It also shows how advances in scientific understanding rely on developments in technology. Remote sensing technology in satellites and aircraft is used to monitor changes in the thickness of ice sheets.

The clip shows how both satellites and airborne measuring devices operate. The twin GRACE satellites measure gravity fluctuations over the Earth's surface and ICEsat, which was shut down in February 2010, used a laser altimeter to measure ground topography (surface features). Installed in aircraft, gravity sensors, laser altimeters and radar equipment can record data for both the ice surface and the underlying bedrock, allowing ice thickness to be measured.

The altitude of East Antarctica's ice sheet is decreasing, which means it is thinning and losing ice. The clip explains that any increase in ice added to the ocean from grounded ice will cause sea levels to rise. (This grounded ice is not floating ice, and has contact with rock beneath it.) The discovery of liquid water lakes below the ice sheet has increased concerns that the sheet could slip rapidly into the ocean.

The clip addresses the claim that Antarctic ice is not in danger because the area of sea ice is increasing. Sea ice is seasonal, is mostly formed when sea water freezes, and consequently has no effect on sea levels. Loss of grounded ice, however, does cause sea levels to change. As the concerned scientists in the clip discuss, Antarctica is increasingly losing much of this ice, although they note that predictions on how much sea levels may rise vary.

More videos like this in:

Natural and man-made impacts on ecosystems

Related information:

› Catalyst story archive featuring story transcript

Metadata © Australian Broadcasting Corporation and Education Services Australia Ltd 2010 (except where otherwise indicated). Digital content © Australian Broadcasting Corporation 2010 (except where otherwise indicated). You may view, display, print out, copy and modify this material for non-commercial educational purposes provided you retain all acknowledgements associated with the material.