The Perito Moreno Glacier is located in Los Glaciares National Park (Patagonia, Argentina). The glacier is 5 km wide and has a height of 74 meters. It covers an extension of more than 200 square kilometers. This weekend tourists flock (go in large numbers) to see how the glacier will break once again. This rupture happens every four or five years and it is a huge tourist attraction. Why does the glacier break?
Periodically the glacier advances over the L-shaped Lago Argentino 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 the height of the dammed water finally breaks the ice barrier holding it back, in a spectacular rupture event.
Here you see a video of the 2006 rupture:
What is a glacier?