Sharon Begley of The Wall Street Journal is one of the finest science reporters around. Her Friday column was typically interesting. It's about how global warming might lead to increased tectonic and volcanic activity:
One cubic meter of ice weighs just over a ton, and glaciers can be hundreds of meters thick. When they melt and the water runs off, it is literally a weight off Earth's crust. The crust and mantle therefore bounce back, immediately as well as over thousands of years. That "isostatic rebound," according to studies of prehistoric and recent earthquakes and volcanoes, can make the planet's seismic plates slip catastrophically, and cause magma chambers that feed volcanoes to act like bottles of shaken seltzer. "It's unavoidable that glacial retreat will induce tectonic activity," says geoscientist Allen Glazner of the University of North Carolina, Chapel Hill.
Obviously, these predictions are pretty hypothetical. But I'm not sure I want to live in a world where Sweden, Iceland and Northern Canada are full of Krakatoas...
[Thanks to the astute comments of Markk, I though I should make it clear that not all areas of the globe are equally affected by glacial retreat. Geologic studies have only shown that volcanoes in Iceland, the Mediterranean, Antarctica, Northern Europe, Northern Canada and eastern California were awakened by the disappearing glaciers.]
Comments (5)
Right - just like all the volcanos we see in the US midwest about 10000 years ago when even bigger glaciers retreated. Wait I can't find any. I am worried about warming, but not because of this.
Posted by: Markk | June 10, 2006 2:45 PM