Antarctic ice Breaking Up Quickly
New evidence has emerged that a large plate of floating
ice shelf attached to Antarctica is breaking up, in a troubling
sign of global warming, the European Space Agency (ESA) said on
Images taken by its Envisat remote-sensing satellite show that
Wilkins Ice Shelf is "hanging by its last thread" to
Charcot Island, one of the plate's key anchors to the Antarctic
peninsula, ESA said in a press release.
"Since the connection to the island... helps stabilise the
ice shelf, it is likely the breakup of the bridge will put the
remainder of the ice shelf at risk," it said.
Wilkins Ice Shelf had been stable for most of the last century,
covering around 16,000 square kilometres (6,000 square miles),
or about the size of Northern Ireland, before it began to retreat
in the 1990s.
Since then several large areas have broken away, and two big breakoffs
this year left only a narrow ice bridge about 2.7 kilometres (1.7
miles) wide to connect the shelf to Charcot and nearby Latady Island.
The latest images, taken by Envisat's radar, say fractures have
now opened up in this bridge and adjacent areas of the plate are
disintegrating, creating large icebergs.
Scientists are puzzled and concerned by the event, ESA added.
The Antarctic peninsula -- the tongue of land that juts northward
from the white continent towards South America -- has had one of
the highest rates of warming anywhere in the world in recent decades.
But this latest stage of the breakup occurred during the Southern
Hemisphere's winter, when atmospheric temperatures are at their
One idea is that warmer water from the Southern Ocean is reaching
the underside of the ice shelf and thinning it rapidly from underneath.
"Wilkins Ice Shelf is the most recent in a long, and growing,
list of ice shelves on the Antarctic Peninsula that are responding
to the rapid warming that has occurred in this area over the last
fifty years," researcher David Vaughan of the British Antarctic
Survey (BAS) said.
are showing that we were being too conservative, when we made
the prediction in the early 1990s that Wilkins Ice
Shelf would be lost within 30 years. The truth is, it is going
more quickly than we guessed."
In the past three decades, six Antarctic ice shelves have collapsed
completely -- Prince Gustav Channel, Larsen Inlet, Larsen A, Larsen
B, Wordie, Muller and the Jones Ice Shelf.