Related articles

Arctic sea ice falls to third-lowest extent, downward trend continues
Greenland ice sheet larger contributor to sea-level rise
Ice bridge supporting Wilkins Ice Shelf collapses
Arctic is literally on thin ice
Permafrost threatened by rapid retreat of Arctic sea ice
Earth impacts linked to human-caused climate change
Tasman Glacier retreat is extreme
Melting Arctic summer sea ice reaches lowest level
UN stark predictions of impact of climate change
Scientists find lakes and rivers beneath fast moving Antarctic ice that lubricate flow
UN delivers warning on the catastrophe of climate change
Carbon dioxide rate is at highest level for 650,000 years
Now it is up to the world's political leaders to deliver more than hot air
Climate change reduces ocean food supply, threatening marine ecosystems
Arctic summer sea ice falls below normal for fifth year, despite a cool August
Rapid changes in Arctic sea ice
Melting permafrost methane emissions: The other threat to climate change
Ice bubbles reveal biggest rise in CO2 for 800,000 years
A disaster to take everyone's breath away
3 degrees: Chief scientist warns bigger rise in world's temperature will put 400 million at risk
Survey detects significant Antarctic ice mass loss
Greenland ice loss doubles in past decade, raising sea level faster
Global warming: Severe glacial reduction in southern Alaska
Environment in crisis: 'We are past the point of no return'
World is at its hottest since prehistory
2004 fourth warmest in over a century
Antarctic Peninsula glaciers surge when ice shelf breaks up
South American glaciers melting faster, changing sea level

Home > Environmental issues > Global warming > Article     

Antarctic ice shelf disintegration

25 March 2008
National Snow and Ice Data Center (NSIDC), British Antarctic Survey (BAS), and Earth Dynamic System Research Center, National Cheng Kung University

Satellite images reveal that a 13,680 (5,282 sq.mile) ice shelf has begun to collapse because of rapid climate change in a fast-warming region of Antarctica.

The Wilkins Ice Shelf is a plate of permanent floating ice on the southwest Antarctic Peninsula. The western Antarctic Peninsula has had the biggest temperature increase on Earth in the last 50 years, rising 0.5°C (0.9 °F) each decade.

NSIDC Lead Scientist Ted Scambos, who first spotted the disintegration in March, said, "We believe the Wilkins has been in place for at least a few hundred years. But warm air and exposure to ocean waves are causing a break-up."

This latest ice shelf collapse is a strong indication that global warming is changing Antarctic ice faster than prevously predicted.

The Wilkins Ice Shelf began its collapse on February 28th when a large iceberg, 41 by 2.5 kilometers (25.5 by 1.5 miles), fell away from the southwestern front, triggering a runaway disintegration of 570 (220 sq.miles) of the shelf interior (images right).

The edge of the shelf crumbled into the sky-blue pattern of exposed deep glacial ice that has become characteristic of climate-induced ice shelf break-ups such as the Larsen B in 2002. (image centre right)

A narrow beam of intact ice, just 6 km (3.7 miles) wide was protecting the remaining shelf from further breakup as of March 23 (image bottom right and below).

Image: National Snow and Ice Data Center (NSIDC)

View larger image

Ice shelves hold back glaciers, which if unleashed, can accelerate and raise sea level. Scambos said, "The Wilkins disintegration won't raise sea level because it already floats in the ocean, and few glaciers flow into it."

"However, the collapse underscores that the Wilkins region has experienced an intense melt season. Regional sea ice has all but vanished, leaving the ice shelf exposed to the action of waves."

With Antarctica's summer melt season drawing to a close, scientists do not expect the Wilkins to further disintegrate in the next several months. "This unusual show is over for this season," Scambos said.

Above: Arial photo from an aircraft of the sudden, massive break-up of the Wilkins Ice Shelf.
Photo: British Antarctic Survey (BAS)

View 2 larger images

Professor David Vaughan of BAS predicted in 1993 that the northern part of the Wilkins Ice Shelf was likely to be lost by 2024 if warming on the Peninsula were to continue at the same rate.

He says, "Wilkins is the largest ice shelf on the Antarctic Peninsula yet to be threatened. I didn't expect to see things happen this quickly. The ice shelf is hanging by a thread."

Above: Satellite images of the collapse of the Wilkins Ice Shelf.  Images, National Snow and Ice Data Center (NSIDC), University of Colorado

Below: A close-up satellite image covering one-mile (1800 metres) by 2 miles (3200 metres) of the broken up portion of the Wilkins Ice Shelf.
Image, NSIDC/Courtesy of Cheng-Chien Liu/NSPO.

View larger image


Copyright © 2008 TerraNature Trust. All rights reserved.

home | sponsors | latest news & events | join - donate | contact information | projects
volunteer activities | about us | site map | environmental issues | New Zealand ecology