(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.