It took decades for global warming to slowly melt the surface of the Larsen B Ice Shelf on the Antarctic Peninsula, forming nearly 3,000 lakes. But at the end of the Antarctic summer of 2002, all the lakes drained away in the space of a week. And then the 2,700-square-kilometre ice shelf, which was some 220 metres thick and probably had existed for some 12,000 years, rapidly disintegrated into small icebergs, leaving glaciologists scratching their heads.
The researchers showed that if there are many lakes on an ice shelf, the disappearance of one lake could result in fractures under others — an effect that can spread rapidly throughout the ice shelf. “This chain reaction could explain why the lakes drained all together,” MacAyeal said.
Most of the lakes were about 1,000 metres wide, according to a poster presentation at the same meeting by study co-author Alison Banwell. Once drained, each would leave behind a ring fracture about 4,000 metres wide. When lakes are tightly packed together, as they were on the Larsen B ice shelf, the chain of fracturing would result in thin icebergs calving off, Banwell said.
via Chain reaction shattered huge Antarctica ice shelf : Nature News & Comment
The Committee to Nuke Elysium 