"Severe earthquakes in Haiti, Chile and now Japan have experts around the world asking whether the world's tectonic plates are becoming more active — and what could be causing it.
Some scientists theorize that the sudden melting of glaciers due to man-made climate change is lightening the load on the Earth's surface, allowing its mantle to rebound upwards and causing plates to become unstuck.
These scientists point to the historical increase in volcanic and earthquake activity that occurred about 12,000 years ago when the glaciers that covered most of Canada in an ice sheet several kilometres thick suddenly melted.
The result was that most of Canada's crust lifted — and is still rising.
Scientists have discovered that the accelerated melting of the Greenland ice sheet over the last 10 years already is lifting the southeastern part of that island several millimetres every year.
The surface of the Earth is elastic. A heavy load such as a glacier will cause it to sink, pushing aside the liquid rock underneath.
The Greenland glacier is about three kilometres at its thickest and it is believed that its weight has depressed sections of the land under the glacier about one kilometre. In fact, the weight of the glacier is so great that significant portions of Greenland have been pushed well below sea level."
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