A 25-mile-long ice bridge that linked the Wilkins Ice Shelf to Charcot Island on the Antarctic Peninsula has collapsed. NASA satellite imagery shows that the bridge's disintegration occurred sometime between March 31 and April 6. Scientists had been keeping a close eye on the bridge since last March, anticipating its collapse following dramatic changes that have taken place on the Wilkins Shelf in recent years.
The Wilkins Ice Shelf first began to break up in the 1990s, and in 2008 it underwent three significant breakups. From the early 1990s to 2008, the total area of the Wilkins dropped from 6,700 square miles to 4,000 square miles, following a pattern of ice shelf instability that has occurred on the Antarctic Peninsula in recent years. Then last March, the Wilkins suddenly lost 160 square miles in a dramatic retreat.
Ice shelves are thick slabs of ice that extend from coastlines out over the ocean. Because they are exposed to both warm air and warm ocean water, they tend to respond more rapidly to rising temperatures than ice sheets or glaciers do. The loss of the ice bridge will now unleash a mass of large ice fragments and icebergs that will drift into the Southern Ocean.
During the past several decades, the northernmost ice shelves on the Antarctic Peninsula have retreated dramatically, and scientists believe the changes are in response to atmospheric warming in the region. The most dramatic changes have taken place on the Larsen Ice Shelf, which is divided into regions A, B, C, and D. In January 1995, about 580 square miles of the Larsen A suddenly disintegrated into small icebergs. Then in 2002, satellite data captured an even larger collapse when 3,250 square miles of the Larsen B disintegrated -- releasing about 720 billion tons of ice into the Weddell Sea.Because an ice shelf acts as a barrier between glaciers and the ocean, the loss of a shelf can permit glaciers to start flowing into the ocean at an accelerated rate, which can contribute to sea level rise. Following the loss of the ice bridge, researchers are carefully monitoring the Wilkins Ice Shelf to see if any additional breakup occurs.
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Antarctic sea ice at 30% above normal?
http://wattsupwiththat.com/2009/04/08/polar-ice-worries-north-and-south/
hahaha that is a total farce simply because of a) the fact that the charts are only 365 days and b)it shows the snows pack magically increasing from October until it peaks in April... maybe it has something to do with seasons??? hahaha
knowledge-is-power -- If so, then I presume you are quite powerless. Look at the 30 year chart in the article. As the article states, it shows a 5% per decade growth in Antarctic sea ice. It seems that the laugh is on you.
The article is misleading and alarmist. Look at Google Earth, and compare the size of the ice shelf to the size of Antarctica. It's a miniscule area, compared to the entire continent. The real news is the steady increase of Antarctic sea-ice -- but, we're only shown what the global warming alarmists want us to see.
This is a non story. We are talking about ice now? kinda silly.
from Kailua Kona, HI
wsugaimd
The penninsula of Antarctica, where Charcot Island is located, is part of the Pacific Ring of Fire. There are volcanoes under the ice shelf heating things up. Hense the collapse as lubricated ice now slides over the rocky continent.
I hope the whole thing melts! we are running out of room on this tiny planet and could use another continent to inhabit :)
Run for hills....the oceans are rising from melting ice.
Ice shelves breaking up due to atmospheric warming? I wish Popsci would name the scientists who draw such conclusions. How do they rule out ocean water temperatures (a remnant of the last El Nino cycle)as the cause?
Aren't there any ocean water temperature measuring stations around the peninsula? If not, why?. It seems we just don't fully understand the dynamics and causes yet, so conclusions seem highly premature.
Look carfully at the shadows. The April image is lit up by a very low lying sun. This enhances the fissures in the ice cover making it appear to be broken up when it is likely no different from the march image. If anything there appears to be more overall ice cover in the April image than in the March image. As winter nears in the southern hemisphere, naturally, we can expect to see more ice.
Does it really matter? The ice is getting thicker in the eastern part of the continent and more than offsetting any loss on the Peninsula:
Change is a cold certainty
http://www.theaustralian.news.com.au/story/0,25197,25347937-11949,00.html
lensman51: Most inhabited land is low level on our existing continents and a fair part of that inhabited land is coastal. A small rise in sea level by loss of Antarctic and other ice (earlier comment said to be a good thing, provocatively?) will have a major impact on humanity!!!
More than half the world's population lives within 60 km of the shoreline, and this could rise to three quarters by the year 2020 (source: www.globaloceans.org)
If there gets to be a few thousand square kilometers ice free in the Antarctic and if farm fishing is not an option, there are not many crops that grow well on bare rock!
It takes a long time for soil fertility to increase and all the known main food crops are only viable within tight temperature bands and the warmer Antarctic climate may not be warm enough for their liking.
If you throw in changes in the salinity of the ocean then the circulatory dynamics of the world's oceans (called the Ocean Conveyor)could cause a sudden and long term new pattern of ocean currents. Its the difference between a mild or harsh climate at higher latitudes were warm currents run alongside coastal areas.
Air temperature above the oceans warmed by just a few degrees could stoke up the power of hurricanes as well as significant changes in the 'Jetstream' and other wind patterns around the planet so long standing climatic changes could be the result.
Experts can't predict the detail but quite a few accept the idea of sudden change at an unknown tipping point. Loosing Ice Bridges of some considerable size seems to me to be consistent with that tipping point process: i.e. we will wake up one morning to see significant change which is a bit late in the day to complain about or act on.
Ice that has melted means less sunlight reflected so that the oceans warm up and as global temperature increases, re-freezing is ruled out awaiting other changes such as a major volcanic dust cloud around the earth to drop surface temperatures down again.
The Arctic and Greenland are not doing too well with really big numbers involved: ice down by up to 57% at the September to September assessment point between 1953 and 2006 (source J Stroeve, MM Holland, W Meier, T Scambos, M … - Geophysical Research Letters, 2007 - smithpa.demon.co.uk).
Does anyone want to comment on these chilling facts?
we've all watched 'an inconvenient truth'... but thank you.. I dont call the facts chilling as much as- this is just something thats happening and the planet, and its inhabitants will adapt, just like any other climate change in the past.
Wow a lot of silliness about a little chunk of ice! Didn't any of these brilliant "scientists" learn that ice is 11% larger than water? How is melting-shrinking ice going to raise ocean levels?
Also how are these "scientists" predicting weather-temp-climate 50 years into the future when no one can tell me with any accuracy how hot it will be TOMORROW?
I also haven't heard any of these "geniuses" explain how if it gets hotter and wetter for a period, how cloud cover wouldn't then occur?
It's just common sense, even when it's uncommon...
A great deal of ice and snow is setting on land. Some of that ice and snow have been setting on land for a 100,000 years. If all that 100,000 year old ice and snow were to melt, the water from that melting snow and ice will flow to the ocean, raising ocean levels.
Cloud cover prevents radiationial loss of heat at night. So greater cloud mass will reduce daytime temperatures and raise night time temperatures.
One variable in weather has yet to be added to weather models. Variations in solar radiation, which is suppected in local higher and local lower temperatures, are not measured by ground weather stations or weather satellites. Some day science may advance to the point that satellites and ground weather stations are able to pin point the effects that variations of solar radiation has upon local weather.