Posted on 03/25/2008 11:02:27 AM PDT by NormsRevenge
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.
A GPS equipped robot could cost effectively pilot a blob of fresh water thousands of miles, especially if it navigates into the right current. A plastic wrapper could keep the water contained as it melts. The ice berg could be shaped into an airfoil both horizontally and vertically to take advantage of currents, waves, and winds. A drag chute or anchor could be deployed when the ice berg moves in the wrong direction, causing natural motion to push it in a desired direction. Maybe melting water could somehow be turned into hydro power to drive a propeller or winch to move the ice berg.
If fresh water is worth 60 cents per gallon the average ice berg is worth $40 million. I could retire on one ice berg delivery.
Me too! I think we should petition congress for compensation. Or, at least, an apology!
Nuts to you guys!
My Viking ancestors used to have a nice gig in Greenland. But then this Global Cooling thing happened.
So hey I want my ancestral birth right back. As far as I am concerned you guys can dodge ice burgs.
Did anyone check up on the obvious error in this “scientific” article.
It claims the ice shelf, 25 miles long by 1.5 miles wide, is “ten times” the size of Manhattan. Quick math shows the ice shelf is about 37.5 square miles. According to the government, Manhattan in 31 square miles including adjacent waters, 22.5 miles if only the land is considered. The ice shelf is thus less than twice as large as Manhattan, NOT “ten times” as large.
If they can’t get such basic facts even remotely correct, why trust anything they Claim?
He makes it sound as though the shelf is suspended above the sea; if indeed it were, when it broke the “thread” and fell, the sea level would rise instantly causing a tsunami.
The pictures show the sea ice to be floating so any rise in level has already occurred.
Ice-shelving is an annual, autumnal event, now the refreezing begins and the winter snows are soon to begin.
Without the warming summer waters, there would likely be too little cloud formation and weakened snowfall to replenish the ground in winter.
We do have the scientists word for it that a much greater breakup and a near total melt along the Antarctic shore took place roughly 9,500 years ago for purely natural, though not fully understood, reasons.
But it is now time to restart the bandwagon.
We recently came out of the Little Ice Age in the early 1800’s which claimed a portion of the Earth’s water supply in the form of Ice and snow, captured by the frozen arctic regions at both ends of the Planet.
The water that is available to the Planet is either in solid or liquid form. The warming trend caused by the recent Solar Maximum has reclaimed some of the solid water, but there is now evidence that we may be headed for another “little Ice Age”, because of a sudden and severe lack of Solar activity. This may be why we have suddenly experienced a record cold winter in the Northern Hemisphere on both sides of the World.
Sun Spot activity as recently ceased to a degree that has not been observed since the beginning of the Little Ice Age. Time will prove this theory one way or the other, but the recent Global Warming trend was also observed on other Planets along with ours. Mars lost some of it’s ice cap in the last 10 years along with ours.
Wilkins was a small outpost named after Hubert Wilkins around 1928 after successfully flying in to land on the ice and then fly out once again.
Kind of like emptying and refilling a giant ice cube tray.
Well it goes down after I take a swallow out of it :)
Study Newton’s 3rd law
It is floating on the water while still somewhat bound by the land; the bonds depend on the state of the solid glacier to which it is still attached.
This is the thread to which the fabulous author referred
Shhh....there will be no rational thought allowed, amidst the hysteria!
Their argument is not melt down from surface heat but surface heat warming the surrounding area waters causing the observed melt from the bottom up.
They first must rule out incursions and any sub-surface heating from volcanic activity which is in its infant stage of study.
Because the sheeple that read CNN, won't be bothered to do the math.
They could have said "Ten Times the Size of Alaska" and a significant portion of their readers would have said, "Wow! What's an Alaska?"
Thanks for that information.
I recently saw a study done in relation to a warm Ocean current that had shifted south along the Antarctic coast. There are as many theories about this as there are misguided explanations.
The only explanation for warmer Ocean currents would be Solar radiation increasing the Earth’s water temps. There is also one theory out there that claims Sub sea Volcanism is partly to blame for the warmer water.
Not one drop of submerged ice can melt until the surrounding ocean temperature rises above 32 degrees, which is freshwater ice’s tipping point. It takes a tremendous amount of energy to heat this much water to 32 degrees. I bet the ocean water isn’t above 32 degrees and therefore this isn’t a global warming melting mechanism but something entirely different.
If the name fits, wear it.
FMCDH(BITS)
Peak warming and peak plant species migration here in my yard in Fairbanks was in 1995.
Well aware of it. What does it have to do with the subject at hand?
2. Once broken free of the coast, currents will carry the icebergs to more northern latitudes where they will melt faster.
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