Over the last decade, rock avalanches and landslides have become more common in high mountain ranges, apparently coinciding with the increase in exceptionally warm periods. The collapses are triggered by melting glaciers and permafrost, which remove the glue that holds steep mountain slopes together. Worse may be to come.
Thinning glaciers on volcanoes could destabilise vast chunks of their summit cones, triggering mega-landslides capable of flattening cities such as Seattle and devastating local infrastructure. Meanwhile, ongoing studies by Bill McGuire of University College London and Rachel Lowe at the University of Exeter, UK, are showing that non-glaciated volcanoes could also be at greater risk of catastrophic collapse if climate change increases rainfall.
“We have found that 39 cities with populations greater than 100,000 are situated within 100 kilometres of a volcano that has collapsed in the past and which may, therefore, be capable of collapsing in the future,” says McGuire.
New Scientist, 13 Oct 2010