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Coming geological extreme events (not good for nuclear reactors)

Climate change may stir geological mayhem http://www.newscientist.com/blogs/culturelab/2012/02/climate-change-may-stir-geological-mayhem.html New Scientist,  23 February 2012 Fred Pearce, consultant In Waking the Giant: How a changing climate triggers earthquakes, tsunamis, and volcanoes, geologist Bill McGuire warns we may be waking primordial monsters

IN 2006, London geologist Bill McGuire argued in New Scientist that global warming would trigger epidemics of volcanic eruptions, earthquakes and tsunamis. Now he’s written the book. The story is even scarier writ large….. There is now abundant evidence that catastrophic outbursts of geological activity accompanied past periods
of rapid climate change, for instance, when we shifted in and out of ice ages. The stresses and strains of rising and falling sea levels and the creation and loss of ice sheets triggered these outbursts. Climate change, he says, may already be shaking up the Earth anew.

During the last ice age, the weight of ice suppressed volcanic
eruptions. When the ice melted the land surface lifted, sometimes by
hundreds of metres, reducing pressure below and turning solid rock to
liquid magma. The pent-up rage of the Earth was released. As the ice
age faded, the number of volcanic eruptions grew 50-fold. Global
warming threatens a reprise.
McGuire explains that volcanoes “are primed systems constantly
teetering on the edge of stability and highly sensitive to minuscule
changes to their external environment”. He is not just talking about
geological timescales. The Earth changes shape with the seasons as
water shifts hemispheres, squashing or releasing the land beneath. It
squeezes magma like toothpaste in a tube. In the northern hemisphere,
November to April is volcano season.

As shifting ice and water destabilise hidden faults in the Earth’s
crust, earthquakes join this dance of giants. In recent decades, we
have seen an “unprecedented cluster of massive earthquakes”, McGuire
notes. Since 1900, seven have exceeded magnitude 8.8. Three
“megaquakes” off Sumatra, Chile and Japan ripped the Earth apart in
the past seven years alone.

It could be that something is afoot. Six years ago, McGuire suggested
shrinking glaciers in New Zealand’s Southern Alps might trigger an
earthquake. Cue Christchurch last year.

The climate, we know, has been unusually stable in the past 10,000
years. That meant the world was more geologically stable as well. Now,
as we face future climate chaos, we may also face geological mayhem.
http://www.newscientist.com/blogs/culturelab/2012/02

February 27, 2012 - Posted by Christina Macpherson | resources - print