That is the breaking news today from the National Snow and Ice Data Center (NSIDC) and the British Antarctic Survey:
In the past 50 years, the western Antarctic Peninsula has experienced the biggest temperature increase on Earth, rising by 0.5 degree Celsius (0.9 degree Fahrenheit) per 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.”
Satellite images indicate that the Wilkins began its collapse on February 28; data revealed that a large iceberg, 41 by 2.5 kilometers (25.5 by 1.5 miles), fell away from the ice shelf’s southwestern front, triggering a runaway disintegration of 405 square kilometers (160 square miles) of the shelf interior (Figure 1 — click to enlarge).
That is “seven times the size of Manhattan” as Seth Borenstein of the AP helpfully points out. He notes “The rest of the Wilkins ice shelf, which is about the size of Connecticut, is holding on by a narrow beam of thin ice.” The ice shelf is floating, so it won’t add to sea level rise. Such occurrences are “more indicative of a tipping point or trigger in the climate system,” said Sarah Das, a scientist at the Woods Hole Oceanographic Institute. Back to the NSIDC:
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. A narrow beam of intact ice, just 6 kilometers wide (3.7 miles) was protecting the remaining shelf from further breakup as of March 23 (Figure 2 — click to enlarge).