Massive Antarctic ice shelf set to break loose,

[Dantheman62]

PARIS (AFP) – A Jamaica-sized ice shelf is close to wrenching itself away from Antarctica, following dramatic weakening of an ice "bridge" linking it to the continent, the European Space Agency (ESA) reported Friday.

The icy umbilical cord tying the Wilkins Ice Shelf to two islands on the Antarctic peninsula "looks set to collapse," ESA said.

The evidence comes from radar pictures taken on Thursday by its Envisat Earth-monitoring satellite, the Paris-based agency said in a press release.

Scientists have been keeping a worried eye on this ice shelf for years.

For many, it is a barometer of global warming, which has hit the Antarctic peninsula harder than almost any region on Earth.

The Wilkins Ice Shelf was stable for most of the last century, covering around 16,000 square kilometres (6,000 square miles) before it began to retreat in the 1990s.

By May 2009, an ice bridge, about 2.7 kms (1.7 miles) wide on average and just 900 metres (yards) at its narrowest point, was all that connected it to Charcot and Latady islands.

Over the past year, the ice shelf has lost about 1,800 square kilometres (700 square miles), or about 14 percent of its size, in further breakup events, ESA said.

New pictures show "the beginning of what appears to be the demise of the ice bridge" itself, it added.

This week, rifts formed along the central axis of the bridge and a large chunk of ice broke away. The stress patterns are now expanding rapidly, pointing to a likely imminent collapse of the link.

http://news.yahoo.com/s/afp/20090403...20090403150607

[vagabunda]

Thank you, Dantheman -

I read back in February that the Wilkins was really starting to go. A Spanish team was there and described what seemed to be occurring due to the new ocean surface area being created:


The resulting giant icebergs, some of them 200 metres high are now drifting in the adjoining Antarctic sea. Scientists believe the ice shelf is crumbling as a result of global warming.

A team of CSIC scientists on board the Spanish research vessel “Hespérides” has been in the area assessing the impact of the crumbling ice shelf on the Belinghausen Sea ecosystem, to the west of the Antarctic Peninsula.

Over the past two weeks CSIC scientists have been following the Wilkins ice shelf evolution and have noted that water temperatures are “extraordinarily warm” in the area.

CSIC scientist, Jordi Dachs, reported that his team had found “a very high level of bio-mass and biological production” in areas where the fragments of ice have gone and that there is “abundant fauna, with the largest concentration of humpback whales and leopard seals” they have seen so far in Antarctica.

“We have also found very low levels of CO2 in the sea water, suggesting that the increase in sunlight as the shelf slimmed and elements released by the breaking ice fertilized the water”, added Jordi Dachs.

Pedro Luis de la Puente, captain of the Hespérides research vessel underlined the danger of sailing in these waters, which “have never been fully exposed to a topographic survey as they have been covered in ice up until now”.

The depth of the water is believed to range between 150 and 300 metres but scientists are encountering icebergs that have run aground suggesting different sea bed topography.

The Wilkins ice shelf is to the southwest of the Antarctic Peninsula, 1.600 kilometres from the South American land mass.

“Polar Year is coming to an end (March 2009) and unfortunately during this period the greatest proven and documented loss of ice mass on both polar caskets has been recorded by the different scientific teams, which is most dramatic”, said CSIC researcher Carlos Duarte.



http://www.esa.int/esaCP/SEMJBATHKHF_Spain_1.html

[Dantheman62]

Thanks for more info vagabunda, and if you're interested here's another thread that has parts on what's going on below Antarctica and all the lakes and rivers below the ice!

http://projectavalon.net/forum/showt...t=core+samples

You have to kinda search through the thread to find the info.

[vagabunda]

hey, thanks for that...lots of good reading.

one more link for you, here's some interesting time-lapse sat imagery taken of Wilkins last year...

http://www.esa.int/esaCP/SEMJBATHKHF_Spain_1.html