Combination of two photos shows Argentina's Perito Moreno glacier before (L, taken July 4, 2008) and after (R, taken July 9, 2008) the collapse of the roof of an ice tunnel, near the city of El Calafate in the Patagonian province of Santa Cruz, southern Argentina. (Xinhua/Reuters File Photo) Photo Gallery>>>

    BUENOS AIRES, July 9 (Xinhua) -- Dozens of people witnessed Wednesday the collapsing of the arch or bridge of ice from the Perito Moreno glacier, located in El Calafate, in Santa Cruz province in the Argentine Patagonia.

    Only around 40 people had the chance to see the phenomenon, despite the fact that experts had forecast the fracture of the arch.

    The cracking of the natural bridge or arch began at 11:20 local time (1420 GMT) when only a few people were inside the national park of Los Glaciares.

    However, millions more have been able to see on the Internet (www.epatagonia.gov.ar/glaciar) the moment when the huge ice wall more than 50 meters long collapsed, making a tremendous noise amid shouts and applause from the people present.

This combination of two photos shows Argentina's Perito Moreno glacier before (L, taken July 4, 2008) and after (R, taken July 9, 2008) the collapse of the roof of an ice tunnel, near the city of El Calafate in the Patagonian province of Santa Cruz, southern Argentina. (Xinhua/Reuters File Photo) Photo Gallery>>>

    This is the first time the breaking of the Perito Moreno glacier has happened in wintertime, which has generated concern for what specialists call "the consequences of the global warming."

    The Perito Moreno glacier, with an extension of 250 square kilometers, is considered one of the most important drinking water reserves in the world.

    It is five kilometers wide at its face and 30 km in length, with an average height of 60 meters above the surface of the water of Lake Argentine, into which huge chunks of ice fall. The last rupture was in the summer of 2006.

    The glacier takes its name from Francisco Pascacio Moreno, an expert (perito) and exceptional Argentine researcher who dedicated his life to studying Patagonia.

    This ice arch or bridge falls every four to five years during the Southern Hemisphere's summer (from September to May), but on this occasion it ruptured in winter.