Vast Antarctic Ice Shelf on Verge of Collapse

[yiozik]

LINK:
To view links or images in this forum your post count must be 1 or greater. You currently have 0 posts.


A vast ice shelf hanging on by a thin strip looks to be the next chunk to break off from the Antarctic Peninsula, the latest sign of global warming's impact on Earth's southernmost continent.

Scientists are shocked by the rapid change of events.

Glaciologist Ted Scambos of the University of Colorado was monitoring satellite images of the Wilkins Ice Shelf and spotted a huge iceberg measuring 25 miles by 1.5 miles (41 kilometers by 2.5 kilometers - about 10 times the area of Manhattan) that appeared to have broken away from the shelf.

Scambos alerted colleagues at the British Antarctic Survey (BAS) that it looked like the entire ice shelf - about 6,180 square miles (16,000 square kilometers - about the size of Northern Ireland)- was at risk of collapsing.

David Vaughan of the BAS had predicted in 1993 that the northern part of the Wilkins Ice Shelf was likely to be lost within 30 years if warming on the Peninsula continued at the same rate.

"Wilkins is the largest ice shelf on the Antarctic Peninsula yet to be threatened," he said. "I didn't expect to see things happen this quickly. The ice shelf is hanging by a thread - we'll know in the next few days and weeks what its fate will be."

Aircraft reconnaissance

The BAS scientists sent an aircraft out on a reconnaissance mission to survey the extent of damage to the ice shelf.

Jim Elliot, who captured video of the breakout said, "I've never seen anything like this before - it was awesome. We flew along the main crack and observed the sheer scale of movement from the breakage. Big hefty chunks of ice, the size of small houses, look as though they've been thrown around like rubble - it's like an explosion."

An initial iceberg calved away from the Wilkins Ice Shelf on Feb. 28. A series of images shows the edge of the ice shelf proceeding to crumble and disintegrate in a pattern characteristic of climate-caused ice shelf retreats throughout the northern Antarctic Peninsula. The disintegration left a sky-blue patch of hundreds of large blocks of exposed old glacier ice floating across the ocean surface.

By March 8, the ice shelf had lost just over 220 square miles (570 square kilometers) of ice, and the disintegrated ice had spread over 540 square miles (1,400 square kilometers). As of mid-March only a narrow strip of shelf ice between Charcot and Latady islands was protecting several thousand more kilometers of the ice shelf from potentially breaking up.

The region where the Wilkins Ice Shelf lies has experienced unprecedented warming in the past 50 years, with several ice shelves retreating in the past 30 years. Six of these ice shelves have collapsed completely: Prince Gustav Channel, Larsen Inlet, Larsen A, Larsen B, Wordie, Muller and the Jones Ice Shelf.

Antarctic warming

The Wilkins Ice Shelf was stable for most of the last century until it began retreating in the 1990s. A previous major breakout occurred there in 1998 when 390 square miles (1,000 square kilometers) of ice was lost in just a few months.

"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 it to break up," Scambos said.

The Antarctic Peninsula has warmed faster than anywhere else in the Southern Hemisphere; temperature records show that the region has warmed by nearly 3 degrees Celsius during the past 50 years - several times the global average and only matched in Alaska.

Other parts of Antarctica, including the East Antarctic Ice Sheet, seem to be more stable, though areas of melt have been observed in recent years.

Melting in the Antarctic is different than the recent record melt in the Arctic. Antarctica is composed of ice sheets, or huge masses of ice up to 2.5 miles (4 kilometers) thick that lie on top of bedrock and flow toward the coast, and ice shelves, the floating extensions of ice sheets. Arctic ice is primarily sea ice, some of which persists year-round and some of which melts in the summer and freezes again in the winter.

[yiozik]

Sorry I am late!

THIS JUST IN:

Western Antarctic ice chunk collapses

WASHINGTON - A chunk of Antarctic ice nine times the size of Manhattan has suddenly collapsed, putting an even larger glacial area at risk.

Satellite images show the runaway disintegration of a 220-square-mile chunk in western Antarctica. British scientist David Vaughan says it's the result of global warming.

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

[Apollyon]

An iceberg collapses because of the super weight it has, not because of the pseudo global warming

[Prokomenos]

It all depends... I just wonder why people dont like to believe that global warming is a problem.


To view links or images in this forum your post count must be 1 or greater. You currently have 0 posts.

[yiozik]

Originally Posted by Apollyon
To view links or images in this forum your post count must be 1 or greater. You currently have 0 posts.

An iceberg collapses because of the super weight it has, not because of the pseudo global warming

No there is no "pseudo global warming". This is an event that has occured many times before on earth. Who is causing it might not be know 100% just yet but it is all very real.

WASHINGTON (AFP) - Antarctica's massive Wilkins Ice Shelf has begun disintegrating under the effects of global warming, satellite images by the University of Colorado's National Snow and Ice Data Center showed.

The collapse of a substantial section of the shelf was triggered February 28 when an iceberg measuring 41 by 2.4 kilometers (25.5 by 1.5 miles) broke off its southwestern front.

That movement led to disintegration of the shelf's interior, of which 414 square kilometers (160 square miles) have already disappeared, scientists say.

The Wilkins Ice Shelf is a broad plate of permanent floating ice 1,609 kilometers (1,000 miles) south of South America, on the southwest Antarctic Peninsula.

Now, as a result of recent losses, a large part of the 12,950-square-kilometer (5,000-square-mile) shelf is supported by a narrow 5.6-kilometer (3.5-mile) strip of ice between two islands, scientists said.

"If there is a little bit more retreat, this last 'ice buttress' could collapse and we'd likely lose about half the total ice shelf area in the next few years," NSIDC lead scientist Ted Scambos said in a statement.

"Wilkins is the largest ice shelf on West Antarctica yet to be threatened. This shelf is hanging by a thread," echoed David Vaughan of the British Antarctic Survey, which contributed data on the break-up.

Jim Elliott, who was onboard a British Antarctic Survey Twin Otter aircraft sent to video the extent of the damage, said the scene looked like a bomb site.

"I've never seen anything like this before -- it was awesome," he said in a BAS statement.

"We flew along the main crack and observed the sheer scale of movement from the breakage.

"Big hefty chunks of ice, the size of small houses, look as though they've been thrown around like rubble -- it's like an explosion."

Antarctica has suffered unprecedented warming in the last 50 years -- with several ice shelves retreating and six of them collapsing since the 1970s.

"Climate warming in the Antarctic Peninsula has pushed the limit of viability for ice shelves further south, setting some of them that used to be stable on a course of retreat and eventual loss," Vaughan said.

Vaughan said the Wilkins breakout would not affect sea levels because it was already floating when it broke off.

"But it is another indication of the impact that climate change is having on the region."

Over the past half century, the western Antarctic Peninsula has experienced the steepest temperature increase on Earth, 0.5 degrees Celsius (0.9 Farenheit) per decade.

"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 breakup," said Scambos, who first spotted the disintegration in March.

With the Antarctic summer drawing to a close, scientists do not expect the ice shelf to further disintegrate in the next several months.

"This unusual show is over for this season," said Scambos. "But come January, we'll be watching to see if the Wilkins continues to fall apart."

Ultimately, ice shelf breakup in the Antarctic -- more than 13,000 square kilometers (5,000 square miles) have been lost over the past 50 years -- could significantly increase ocean levels around the world.

In 1995 the Larsen A Ice Shelf -- 75 kilometers (47 miles) long and 35 kilometers (22 miles) wide -- disintegrated, fragmenting into icebergs in the Weddell Sea.

In March 2002, a NASA satellite captured the collapse of Larsen B, which had a surface area of 3,850 square kilometers (1,486 square miles), was 200 meters (656 feet) high, and packed in 720 billion tonnes of ice. It took just 30 days to break apart.

According to some calculations based on the present sea level rise of three millimeters per year (0.11 inches), ocean levels could rise by 1.4 meters (4.6 feet) by the end of the century.

[Apollyon]

Originally Posted by yiozik
To view links or images in this forum your post count must be 1 or greater. You currently have 0 posts.

No there is no "pseudo global warming". This is an event that has occured many times before on earth. Who is causing it might not be know 100% just yet but it is all very real.

WASHINGTON (AFP) - Antarctica's massive Wilkins Ice Shelf has begun disintegrating under the effects of global warming, satellite images by the University of Colorado's National Snow and Ice Data Center showed.
.

I dont deny there are periodically phenomena like that.
The pseudo-comment goes to the global effort of controling minds.
Our ancestors already spoke about periodical heats or frosts that <<stroke>> the earth.