Idlewords.com: The Collapse of the Perito Moreno

"A glacier forms when more snow falls on it than can melt in a given year. This implies the existence of a point (let us call it point A) where so much snow is falling that it can make up for the spectacular daily losses at the glacier's face (point B). There is also a third point, point C, where it is warm and dry and you can sit at an outdoor table drinking beer in the sun. However, the physics of glacier formation ensure that points A and B are very close together, and point C, if it exists at all, is very far away, most likely in El Calafate, eighty kilometers to the east."