The Antarctica Ice Sheets, at least where they used to be !

Changes in the extent and stability of Antarctic ice shelves prompted NSIDC to begin a monitoring program of the major ice streams and outlet glaciers along the Antarctic coast. (click here).

This archive spans back to the late 1980's. We began by using data from the AVHRR Polar 1km data set and in 2001 switched to MODIS level 1B data. Currently 19 areas are being monitored year round. This archive is a selected subset of scenes, generally the clearest and most informative scenes available.

Citing these data: Scambos, T., J. Bohlander, and B. Raup, compilers. 2001, updated current year. Images of Antarctic ice shelves. Boulder, CO: National Snow and Ice Data Center.

Digital media.

For more information on this data set contact NSIDC User Services.

When Antarctica melts it means there is instability of the climate. There is no other 'profound' meaning.

Glacier-ice shelf interactions: In a stable glacier-ice shelf system, the glacier's downhill movement is offset by the buoyant force of the water on the front of the shelf. Warmer temperatures destabilize this system by lubricating the glacier's base and creating melt ponds that eventually carve through the shelf. Once the ice shelf retreats to the grounding line, the buoyant force that used to offset glacier flow becomes negligible, and the glacier picks up speed on its way to the sea. Image by Ted Scambos and Michon Scott, National Snow and Ice Data Center, University of Colorado, Boulder.

A critical feature of an ice shelf is the "grounding line," the point where the underside of the ice shelf detaches from land and floats on the ocean water. If an ice shelf retreats to the grounding line, the shelf's shape changes. More ice protrudes above the water line, and the ocean water exerts little buoyant pressure on the ice. As a result, the flow of the glacier meets very little resistance. In the 18 months following the Larsen Ice Shelf disintegration, glaciers feeding that ice shelf accelerated between three- to eight-fold (Scambos et al. 2004 and Rignot et al. 2004). Similar mechanisms are at work in the Jakobshavn Ice Stream in Greenland (Joughin et al. 2004).

How "W"rong could they be? Any regrets?

This is the collapse of the Larson B Ice Sheet which occurred March 20002 (click here)

This occurred after this article appeared in the BBC News (see below):

Thursday, 27 December, 2001, 20:16 GMT
Low probability of ice collapse (click here)

By Christine McGourty, science correspondent, in the Antarctic
Scientists think there is just a one in 20 chance that the West Antarctic Ice Sheet (WAIS) will collapse in the next 200 years.
More data on the ice sheet is urgently required to be more certain about the future of the ice sheet and possible future sea-level rises
Dr David Vaughan, Bas The integrity of the WAIS is crucial to future sea levels; if all the ice melts in this region of the White Continent, it could raise the oceans by several metres.
The 5% probability of disintegration has been worked out by researchers commissioned by the British Government. Their work will be published in the journal Climate Change next month.
It is the first time a risk assessment of a WAIS collapse has been attempted....

Now, fast forward past the collapse of the Larsen B and following an extremely warm climate in Antarctica this year. I tracked it right here on this blog. The Wilkins Ice Sheet has collapsed in images released today. Bush stated in 2003, "There is no such thing as global warming and carbon dioxide could never be a toxic gas." Really? Does anyone doubt the Wilkins Ice Sheet will completely collapse? If you still don't 'GET IT' then it's because you were educated under "NO Child Left Behind !"

Antarctic ice shelf disintegrating as result of climate change, say scientists (click here)

While the area of collapse involves 160 square miles at present, a large part of the 5,000-square-mile Wilkins Ice Shelf is now supported only by a narrow strip of ice between two islands, said CU-Boulder's Ted Scambos, lead scientist at NSIDC. "If there is a little bit more retreat, this last 'ice buttress' could collapse and we'd likely lose about half the total ice shelf area in the next few years." ...

Global warming blamed for ice shelf collapse (click here)
Last Updated: 12:01am GMT 26/03/2008
An ice shelf of 5,000 square miles in western Antarctica has started to collapse, scientists said.

The disintegration of the Wilkins ice sheet, the largest on the Antarctic Peninsula to be threatened, is more evidence of rapid climate change on the continent, they claimed.
Satellite images from the US National Snow and Ice Data Centre show the rapid disintegration of the Wilkins ice shelf
The British Antarctic Survey said the ice shelf was "hanging by a thread".
Satellite images from the US National Snow and Ice Data Centre showed an iceberg measuring 25.5 miles by 1.5 miles - the size of the Isle of Man - broke off last month.
A large section of the sheet, a broad plate of permanent floating ice around 1,000 miles south of South America, is now held together by a four-mile strip of ice.
The collapse of the shelf had been predicted, but is happening more quickly than expected, scientists said. It is thought the warming of the atmosphere, which has been happening several times faster on the Antarctic Peninsula than the global average, has melted more surface ice, which is weakening the shelf....

Wilkins Ice Sheet Collapses

Wilkins Ice Sheet from 2003
Location Map: MODIS image from 13 February 2003, 13:15 (click here)


This series of satellite images shows the Wilkins Ice Shelf as it begins to break up. The large image is from March 6. The images at right, from top to bottom, are from Feb. 28, Feb. 29 and March 8. The images were processed from the MODIS satellite sensor flying on NASA's Earth Observing System Aqua and Terra satellites. Images courtesy NSIDC, NASA, University of Colorado

Satellite images from the US National Snow and Ice Data Centre show the rapid disintegration of the Wilkins ice shelf