Warmer temperatures might have caused a prehistoric Sicilian volcanic landslide as well as several recent avalanches on the white slopes of Alaska, New Zealand, and the Alps. These two studies are published today in a special issue of Philosophical Transactions of the Royal Society A investigating the thrust of climate change on geological hazards.

UK scientists Kim Deeming, Bill McGuire, and Paul Harrop looked closely at an ancient collapse on Mount Etna in Sicily, concluding that it was likely triggered by a warm and wet period in the early Holocene around 10,000 years ago.

The most prominent feature on Mount Etna is Valle del Bove, a natural amphitheatre over 1,000 times larger than the Colosseum and bounded by kilometre-high cliffs — excavated from the eastern flank of the volcano in a catastrophic collapse. The researchers calculated the amount of time the surface was exposed to extraterrestrial cosmic rays and found that the collapse happened 7,500 years ago, around the time when the weather was warmer and wetter.

Rain and meltwater from snow and ice that cap the volcano can interact with fresh magma, causing pressures to build within the pores of rocks, which destabilizes slopes, they propose. The warmer and wetter conditions to come, the authors suggest, may increase potential for volcano collapses.

This set of 14 papers came out of the Third Johnston–Lavis Colloquium addressing the issue of climate forcing of geological and geomorphological hazards held at University College London in September 2009.

Image: Mount Cook by I. Owens

Full article is published on http://blogs.nature.com/

To read complete article, please click here…