100-Sq.-Mile Ice Island Breaks Off Greenland Glacier 323
suraj.sun sends word of a 100-sq.-mile (260-sq.-km) ice island that broke off of a Greenland glacier on Thursday. "The block of ice separated from the Petermann Glacier, on the north-west coast of Greenland. It is the largest Arctic iceberg to calve since 1962... The ice could become frozen in place over winter or escape into the waters between Greenland and Canada. ... [NASA satellite] images showed that Petermann Glacier lost about one-quarter of its 70-km-long (43-mile) floating ice shelf. There was enough fresh water locked up in the ice island to 'keep all US public tap water flowing for 120 days,' said Prof Muenchow." The Montreal Gazette has more details and implications for Canadian shipping and oil exploration, along with this telling detail: "the ice island’s thickness [is] more than 200 metres in some places... [or] half the height of the Empire State Building." The NY Times has a good satellite photo of the situation.
Re:kdawson - off topic (Score:3, Interesting)
Yes, you can. The ability to do so was added back during the Jon Katz nonsense as I recall, so it's not like this is anything new.
Recover for freshwater? (Score:2, Interesting)
I'm curious what technical challenges would have to be overcome to actually recover this frozen water. Many parts of the world are undergoing severe freshwater shortages. A very large block of frozen water seems like it could be very useful to answer that problem. Could getting at least part of it into into a reservoir be technically / economically possible?
Off the top of my head, I was musing about getting it into the Great Lakes, but the channels and locks in the Great Lakes Waterway are obviously far too small to move something this size. If it were eventually towed to a port, what could be done with it? How fast would it melt?
Re:Clearly a sign of AGW (Score:5, Interesting)
Oh, I just love this argument. It's based on the fact that arctic sea ice is declining to unprecedented levels according to studies using every piece of data and proxy data known, as documented in dozens of peer-reviewed studies, but at the same time, Antarctic ice is increasing, and at times, the combined average is higher than the previous combined average. Never mind that Antarctic sea ice increase is a *forecast* of AGW due to the increased snowfall and increase in flow rates of its glaciers, while Artic sea ice is declining, as expected.
The argument can basically be summed up as this:
Re:Clearly a sign of AGW (Score:4, Interesting)
First off, the frog thing is just a myth. Second, life can adapt, but only with time.
Re:Clearly a sign of AGW (Score:1, Interesting)
Re:Clearly a sign of AGW (Score:2, Interesting)
Re:Clearly a sign of AGW (Score:3, Interesting)
On point of the original post: ice shelves calve. There are momentous dynamic forces at play here. The surface air temperature really has nothing to do with it whatsoever. It would still calve in the absence of any atmosphere at all.
Re:Bad Science (Score:2, Interesting)
Insolation at the top of the atmosphere is approximately 1360 watts per square meter. Where do you get "342?" Are you perhaps considering only part of the spectrum?
http://en.wikipedia.org/wiki/Insolation [wikipedia.org]
Re:Clearly a sign of AGW (Score:5, Interesting)
It's probably true, however unlikely it seems to you, but one of the best proofs doesn't come from animals. Plants don't wander around - Once a tree grows in a spot, it's committed. Some plants in particular drop heavy nuts or seeds that will only get transported as far as animals will move them at the very most, and some spread by runners or similar methods that mean the offspring will always be close to the parent and moving across large distances takes many generations. For one example that's been particularly useful to biologists, evergreens that live on tops of mountains above the deciduous tree line usually stay there unless the climate gets so warm that tree-line moves higher than the mountaintop. Climate change at one rate may let some of these species relocate, but at a faster rate will simply wipe them out locally. In the same way, some plant diseases may spread widely only if the tree-line becomes so low, the mountain peaks are all connected. That's a distinctive, temperature related effect. We can look at plant fossils and make some pretty good estimates of how long it took for prehistoric changes, in particular, there are formulas based on longevity and reproductive frequency that hold if species X stays viable in some area for Y time, the rate of change had to be slower than Z. I't's a pretty good argument if species are now going locally extinct at 10xZ or 50xZ rate, that nothing like that has happened in pre human times, or we wouldn't have living examples of those species. Because some of the currently observed rates can be tens or more times faster than the prehistoric rates, rather than just, say 50% faster, it's considered an unambiguous type of evidence.
To be fair, even this line of reasoning takes a lot of crosschecking. Plenty of legitimate scientific disputes exist over just how big a locale is meaningful, or how many different species should be checked before the results deserve a certain level of confidence, or whether the scars left by a particular plant disease are uniformly distinctive. For some cases, scientists do have to consider other events that may have happened that fast in prehistoric times (Dinos weren't the only thing clobbered by that asteroid 60 million years ago). So, it may be only fair to say, "unless the Cretacious extinctions were really caused by some sort of warming cycle and not a massive shield volcano super-eruption, asteroid impacts, or alien trophy hunters, nothing like this, this fast, has ever happened before." But, within limits such as that, the evidence is mounting.
Re:Clearly a sign of AGW (Score:1, Interesting)
It's not true. The Earth warmed this much, and this fast, from 1900 to 1945. Is that recent enough? There also have been several more significant warmings in the past 15,000 years. It's not hard to find them.
Re:Bad Science (Score:2, Interesting)
That's beautiful, except the 1300 watt figure is already an average. I'm by no means an expert, but I have had a long time interest in solar PV, and the energy at the surface where I live for a flat plate collector aimed at solar noon is quite close to 1000 watts per square meter. Now, a mono or plycrystalline silicon panel, with its indirect bandgap absorption is only going to collect something on the order of 1/5 to 1/10 of that energy, but that doesn't change the fact that it is there.
I actually agree with the overall gist of the original poster's argument. I just think when your rhetoric is expressing agitation at "bad science" and you then go on to make an argument that contains a serious error of fact, well, it undermines one's authority.
I'm not jumping on a high horse here myself. I once in a loud and angry online debate confused hydrocarbons and carbohydrates. We all make mistakes. I expressed mine as a question. I wanted to understand where the figure came from because it didn't match my direct experience with PVs at 45 degrees north.