Chunk of Antarctic ice shelf collapses, putting larger area at risk

[Richard Tafoya]

AP:
http://www.latimes.com/news/nationworld/nation/la-sci-antarctic26mar26,0,7908376.story

A chunk of Antarctic ice about seven times the size of Manhattan suddenly collapsed, putting an even greater portion of glacial ice at risk, scientists said Tuesday.

Satellite images show the runaway disintegration of a 160-square-mile chunk in western Antarctica, which started Feb. 28. It was the edge of the Wilkins ice shelf and has been there for hundreds, maybe 1,500 years.

This is the result of global warming, said British Antarctic Survey scientist David Vaughan.

Because scientists noticed satellite images within hours, they diverted satellite cameras and even flew an airplane over the ongoing collapse for rare pictures and video.

"It's an event we don't get to see very often," said Ted Scambos, lead scientist at the National Snow and Ice Data Center in Boulder, Colo. "The cracks fill with water and slice off and topple... That gets to be a runaway situation."

While icebergs naturally break away from the mainland, collapses like this are unusual but are happening more frequently in recent decades, Vaughan said. The collapse is similar to what happens to hardened glass when it is smashed with a hammer, he said.

The rest of the Wilkins ice shelf, which is about the size of Connecticut, is holding on by a narrow beam of thin ice. Scientists worry that it too may collapse. Larger, more dramatic ice collapses occurred in 2002 and 1995.

[tiger_rascal]

Wow.

But, larger collapses have occurred in the past.

[Richard Tafoya]

The part that collapsed may trigger further collapses, and is in the part of the continent that is warming, so it could produce enough melt-off to raise ocean levels and trigger flooding of low-lying land areas thousands of miles away.

[Java]

Also another reason in addition that this may trigger further collapses is the fact this large area of ice is no longer acting as an inhibitor to the flow of ice to the sea from farther inland, and with inland meltoffs in the past seeping through the ice to the bottom of the ice sheets upon land usually within a matter of weeks of surface melting, this water that collects below the ice acts as a lubricant which helps speed up the flow of ice sheets towards the sea. This same effect has been recently noted in Greenland's ice sheets as well through satellite observations over the years in combination with local gravity fluctuations associated with the loss of ice mass which can be measured indirectly by slight variations from the normal orbital positions of these satellites as can be measured quite accurately to within centimeters of where these satellites should be at any given time and place.

In addition, with all this ice entering into the oceans a cooling effect can occur which may cause the weather patterns to change (as well as sea currents too) and even create cooler temperatures as well, but temperatures alone are no measure for global warming. Its the BTUs being absorbed which still turn 32 degree F (0 degree C) ice into 32 degree F (0 degree C) water that is the real latent culpret here and is most often overlooked by the media (who for the most part have little or no understanding of BTUs), but those who know their science also know there is a very huge problem that is accelerating even faster than most have realised!