Why was there such a build-up of snow in the Alps above Galtür in February 1999?
The Alps are a spectacular mountain range over 3,000 metres high with a sharp, steep landscape. In February 1999, a series of low pressure systems persisted that brought continuous heavy snowfall. The result was that in one month, more than twice the amount of snow fell as usually falls during the whole winter from December to April. How are avalanches created? Avalanches occur when a large amount of snow and ice or rock falls suddenly down a mountainside. There are two main types of avalanche – dense flow avalanches or ‘wet’ avalanches, sometimes called slab avalanches, and powder snow or ‘dry’ avalanches. Most of them happen during or soon after storms. Slab avalanches are usually more deadly than powder snow avalanches but this disaster was a dry avalanche. Avalanches happen when a weak layer of snow can no longer support the weight of the snow above it and the overlying snow cracks and breaks away. What happened at Galtür and why? Very high winds and low temperatures meant that exc
