Beverly Spicer

We’re learning a lot about glaciers melting these days, but something that may not be common knowledge is that some glaciers break up in short cycles, and are popular observable events. Perito Moreno Glacier in southern Argentina is exactly this sort of glacier and is one of South Americas finest tourist attractions, especially for the science-minded. This particular glacier is one of three in South America that are advancing rather than retreating. The pressure caused by the physics of the advance causes it to break up every four years “like clock work, give or take a week,” according to one source. Another says Perito Moreno regularly breaks up, but with a frequency of once every one to ten years rather than every fourth year.

It’s nice to know that not all glaciers are retreating or melting, and that some have cycles of changing appearance that are very short. Given that we think of the cyclical nature of glaciers in terms of thousands of years, somehow I find it reassuring, if counterintuitive, that the breakup doesn’t indicate retreat. It makes me wonder how many glaciers there are that display this kind of aberrant, dramatic activity. I hope some of you are glacialogists and can fill us in.

Wikipedia has an article about Perito Moreno, and Google Images has many photos of the mercurial glacier. And if you missed it at the beginning of this post, for a moving view take a look at this wonderful video of Perito Moreno breaking up to the applause of many spectators.