A photo from open sources
It took decades of global warming to slowly melted the surface of the Larsen ice shelf on Antarctic Peninsula, forming nearly 3,000 lakes. But at the end Antarctic summer 2002, all lakes dried out in one weeks. And then 2700 square kilometers of the ice shelf, which was about 220 meters thick and may have existed in for 12,000 years, quickly broke up into small icebergs, leaving a glaciologist an incident worth thinking about.
It was “like breaking glass from an abandoned stone,” said University of Chicago Geophysicist Douglas MacAyeal Last Week at the International Glaciological Society, gathered in Beijing.
Researchers have wondered starting with the fact that, may have caused the sudden desiccation of the lakes, and whether this was the reason destruction of the ice shelf. Today’s research team on led by MacAyeal, ready to answer these questions. Using a mathematical model originally created by Russian scientists, to understand how to drive loaded trucks across frozen rivers, MacAyeal and his team found that drying one lake on an ice shelf changes the stress area in neighboring areas, cause a circle of destruction around the lake.
As the scientist explained at the meeting, it is caused by ice elasticity. The ice bends in response to a heavy load and comes in the norm when the load is removed. Searing the lake is equivalent to as if it had just been removed from the glacier. They also came to the conclusion that the disappearance of one lake can lead to fractures in others places and this chain reaction will spread rapidly throughout to the glacier. This may explain almost simultaneous drying. lakes.
Most of the lakes were 1000 meters wide, co-author reports Alison Banwell research. After the lake dried up, behind it remained a fault of almost 4,000 meters. When the lakes are located tight to each other, as it was on the Larsen B glacier, a chain faults will lead to the formation of new icebergs. With this statement many of their colleagues agree. But according to Christina Hulbe, geophysics from the University of Otago in New Zealand, still worth take a closer look at the natural propagation of cracks, caused by prolonged melting and an option with ever-increasing the temperature of the oceans.
By the way, it is from the breakaway of the Larsen glacier that begins feature film “The Day After Tomorrow”.
Antarctica
