In medieval times the Matterhorn in Switzerland was believed to contain a ruined city inhabited by the souls of avalanche victims. We know more about the surface of the moon than we do about the centre of an avalanche. Montroc in the French Alps was hit in 1999 by a 60mph avalanche made up of 40,000 tons of snow. Twelve people were killed. 90% of people caught in avalanches start them themselves. In world war one the Germans realised ...