Wilkins ice shelf winter collapse – a troubling sign of rapid global warming say scientists.

This week the European Space Agency released some new images taken by its Envisat remote sensing satellite that show the breakup of the ice bridge connecting the Wilkins ice shelf to Charcot island. The breakup of the bridge is significant because it stabilises the shelf and its collapse could lead to the disintegration of the whole ice shelf. This occurrence has surprised scientists and the agency is quoted as saying:

“This break-up is puzzling to scientists because it has occurred in the Southern Hemispheric winter and does not have characteristics similar to two earlier events that occurred in 2008, which were comparable to the break-up of the Larsen-A and -B ice shelves.”

“The persistently low sea ice cover in the area and data from some interesting sources, electronic seal hats [caps worn by seals that provide temperature, depth and position data] seems to suggest that warm water beneath the halocline may be reaching the underside of the Wilkins Ice Shelf and thinning it rapidly – and perhaps reaching the surface, or at least mixing with surface waters.”

The disturbing aspect of this most recent collapse is that it indicates that the time frame previously estimated for the breakup of the Wilkins ice shelf of thirty years appears now to be conservative. The shelf now seems likely to succumb sooner than expected because of the increased warming that has occurred in recent years.

Climate Skeptics in Australia  like elements of the Coalition cannot continue to pursue a policy of climate change denial and obstruction in the face of such rapid changes to Antarctica.

The fact that even the cold temperatures of winter cannot stop the effects of the oceans warming on Antarctica should disturb those that continue to push for delay in action. It is time to heed the warning signs and do something about it.

PHOTO OF THE DAY:

The following are the images released by the European Space Agency and further information can be read at their site at the following link.

Annotated image of Wilkins Ice Shelf acquired on 9 July 2008 by Envisat’s ASAR instrument, showing the ice bridge connecting to Charcot Island and Latady Island (bottom left). A new fracture that could open the ice bridge is visible at the bottom of the ice bridge.

Credits: ESA

Satellite image of Wilkins Ice Shelf

Compare this with an image from 1992.

Satellite image of Wilkins Ice Shelf 1992

This image of the Wilkins Ice Shelf was acquired on 13 January 1992 using ERS-1’s SAR instrument. Shades of grey have been assigned to backscatter values, white indicates no backscatter, black indicates high backscatter.

Credits: ESA

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~ by abstraktbiblos on Saturday, 12 July, 2008.

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