Argentine Glacier (Perito Moreno) Breaks in Winter for the First Time Ever
by Paula Alvarado, Buenos Aires on 07. 7.08
(Picture: Santa Cruz tourism office via La Nacion newspaper.) The Perito Moreno is one in a group of 48 glaciers located in the Andes, near the limits between Santa Cruz province and the Chilean frontier. Its break is a periodic event caused by the glacier's advance on the lake where it's located, and so far it had only happened during the summer, when the ice is weaker. This year, the process began last Friday and the glacier is about to break in winter for the first time in history.
Even though specialists have not officially linked the phenomenon with global warming, the mayor from the National Park that shelters the glacier has recognized in several media declarations it could be due to higher temperatures and stronger water pressure. The Perito Moreno glacier, however, is one of the only three that are not retreating in Patagonia.
Perito Moreno's periodic breaks
According to Wikipedia, the periodic breaks in Perito Moreno take place as follows:
"The glacier advances over the Argentine Lake forming a natural dam which separates the two halves of the lake when it reaches the opposite shore. With no escape route, the water-level on the Brazo Rico side of the lake can rise by up to 30 meters above the level of the main lake. The enormous pressure produced by this mass of waters finally breaks the ice barrier holding it back in a spectacular rupture event".
When the break happens, it becomes a tourist attraction and a national news in Argentina. However, this year the break will probably be seen only by locals, as it's low season and most hotels in that area of Patagonia remain closed.
Strange weather events in Argentina
The fact that this will happen for the first time in winter adds one more strange event to the Argentine weather chronicles of the last year.
Others have been the first snow in 90 years in Buenos Aires in July 2007, and the sight of two waterspouts (tornado-like shapes over water) also in Buenos Aires last March 2008 (see links to our coverage of those below).
Different specialists have mentioned the change in average temperatures as possible causes for these events, but have not officially linked them all together with climate change or global warming.
Sources
Perito Moreno Glacier in Wikipedia
Argentine National Agency on the break of Perito Moreno in winter (in Spanish)
Clarin newspaper on the winter break of Perito Moreno (in Spanish)
Other weather news in Argentina
Snow in Buenos Aires: Was it Global Warming?
Crazy Weather Causes Tornado in Buenos Aires
You can cite me and Og, who have been watching this glacier for the past 5 billion years, for the proposition that this thing has NEVER melted in the winter. It's been a long time waiting for this to happen, let me tell ya.
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NOTE FROM WRITER: Not sure I understand correctly the comment, but the article does not say 'melt', the break is a periodic event that usually took place in summer every four years.
I think what the first commenter is trying to get at is that you're going out on a limb to say that this has "never" happened in the winter before. People citing meteorological events that are unprecedented, often as "proof" of climate change, use this rhetoric too often. Similar examples are the North Pole being ice-free or the Northwest Passage being passable, "for the first time". But how would you know if this has never happened before? The only reason we know the Pole is ice free is because we have satellites to see this. If the glacier described above had broken in winter, say, 150 years ago, would there have been anyone around to record the event?
On the plus side, Ms. Alvarado at least pays lip service to the fact that unusual weather in BA has not been "officially" linked to climate change.
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NOTE FROM WRITER:
Thanks for that comment. How dumb, I didn't get the irony.
I omitted to say that records for the break started in 1917. So there's almost a century of data to compare to.
Apart from that, I guess you can always find arguments to believe in anything you want to believe in. Even with a century of data someone could say "oh, but 250 years ago it could have been different". To me that's a little too picky, but I respect it. It's up to each reader.
I live in Argentina and this was just weird for us. Same than the snow and waterspouts last year. I cannot say those are proofs of something, just mention they're weird things happening in the weather and that they might be linked to change in temperatures.
I hope you don't mind if I correct a few of your statements:
(1) the break-up process did not start a few days ago, but has been expected since March at least. The "winter collapse" of the bridge is therefore a LATE phenomenon, not an early one
(2) if the bridge crashes down every two years, it means it takes less than that time to build a new bridge
(3) both of the above indicate cooler rather than warmer conditions. In fact there is no indication of any warming at all on the Perito Moreno, and as you pointed out the glacier is not retreating
(4) the 1917 break-up and the 1951 one if I am not mistaken they both happened in winter
(5) the Clarin article below (in Spanish) notes how the current episode is happening whilst snow is falling
http://www.clarin.com/diario/2008/07/06/sociedad/s-01709318.htm
Finally, there must be a reasonable way to link stuff to global warming, although I haven't read of any as yet.
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REPLY:
Of course I don't mind you correcting the statements. And I must clear they were published by several media in Argentina, which of course doesn't make them true, but I want to say that so that it doesn't seem like I'm the first to say this. My responses:
1. I'm not sure where you got that from, since according to what I've read the glacier breaks every three or four years and the last break was in 2006.
2. I don't know where it says it breaks every two years, I've read everywhere it's every three or four.
3. That depends on the two facts I mentioned before. And I did not mention there's global warming there, I'm just noting this was unexpected.
4. That I don't know. The mayor from the national park said everywhere it's the first time. Maybe he doesn't know these facts for sure and maybe all media that published it took the wrong data. I'm not saying that ironically, it can happen as media is made by humans and is not perfect.
5. Yes, but that's not necessary an indication that the ice in the glacier might not have been weaker.
As per your final remark, again, I haven't directly said this is global warming. I just said it's a weird event.
Please let me know if you have information that proofs this otherwise, I have no problem in correcting it.
Thanks.