Skip to comments.Antarctic Ice Shelf Collapse Blamed On More Than Climate Change
Posted on 02/11/2008 3:42:18 AM PST by Brilliant
When the Larsen B Ice Shelf in Antarctica collapsed in 2002, the event appeared to be a sudden response to climate change, and this long, fringing ice shelf in the north west part of the Weddell Sea was assumed to be the latest in a long line of victims of Antarctic summer heat waves linked to Global Warming.
However in a paper published in the Journal of Glaciology, Prof. Neil Glasser of Aberystwyth University, working as a Fulbright Scholar in the US, and Dr Ted Scambos of University of Colorado's National Snow and Ice Data Centre now say that the shelf was already teetering on collapse before the final summer.
Ice shelf collapse is not as simple as we first thought, said Professor Glasser, lead author of the paper. Because large amounts of meltwater appeared on the ice shelf just before it collapsed, we had always assumed that air temperature increases were to blame. But our new study shows that ice-shelf break up is not controlled simply by climate. A number of other atmospheric, oceanic and glaciological factors are involved. For example, the location and spacing of fractures on the ice shelf such as crevasses and rifts are very important too because they determine how strong or weak the ice shelf is.
The study is important because ice shelf collapse contributes to global sea level rise, albeit indirectly. Ice shelves themselves do not contribute directly to sea level rise because they are floating on the ocean and they already displace the same volume of water. But when the ice shelves collapse the glaciers that feed them speed up and get thinner, so they supply more ice to the oceans, Prof. Glasser explained.
Professor Glasser acknowledges that global warming had a major part to play in the collapse, but emphasises that it is only one in a number of contributory factors, and despite the dramatic nature of the break-up in 2002, both observations by glaciologists and numerical modeling by other scientists at NASA and CPOM (Centre of Polar Observation and Modeling) had pointed to an ice shelf in distress for decades previously. It's likely that melting from higher ocean temperatures, or even a gradual decline in the ice mass of the Peninsula over the centuries, was pushing the Larsen to the brink, said co-author Ted Scambos of University of Colorado's National Snow and Ice Data Centre.
The focus of further study is now moving to the Larsen C shelf, a much thicker and apparently more stable area, and while there are at present no signs that this shelf is likely to collapse, Professor Glassers paper will play an important role in informing future study. The keen interest expressed in the paper has also been a boost to Professor Glassers hopes of raising funds to travel to Antarctica this year to conduct some of his research in the field.
The largest Antarctic iceberg ever spotted was by the USS Glacier in 1955. It was twice the size of the state of Connecticut. Check it out.
Professor, you win an all expense paid trip to ...
of interest? ping.
Me and my pet rock,,,,,,,,
"The keen interest expressed in the paper has also been a boost to Professor Glassers hopes of raising funds to travel to Antarctica this year to conduct some of his research in the field."Ding, ding, ding, ding, ding. Jackpot! We have a winner!
Which "victims" and which "heat waves" would those be? And even IF Antarctica is melting, why is that such a bad thing? Seems like the melting ice sheets and rising temperatures (provided that you believe this crap) would free up a bunch of prime real estate. The same goes for up north in Alaska, Canada, Greenland, and Iceland.
This is a novel concept to the scientists?
Not to mention the extended growing season which equals more food and cheaper food, wine grapes being grown in northern climates like Scotland, etc, just like the last time we had a global warm up during the Medieval Warming Period.....
Simultaneous warming on Earth and Mars suggests that our planet's recent climate changes have a naturaland not a human-inducedcause, according to one scientist's controversial theory....
Of course, during the Ice Ages, the glaciers did reach, if not to the equator, certainly a long way in that direction.
If he didn’t add gloal warming back in he would lose his funding and/or his job.
Its the height of the summer in Antarctica right now and temperatures are 3C to 9C below normal so there is NO melting going on in Antarctica this year at all (given only a few areas near the coast reach 0C in the summer.)
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