Most of the rough ground consists of a vast grass land and frozen desert covers the rest. The grass zone is 5,000 meters, the alpine zones is 4,000 meters and higher. Data taken from the World Book Encyclopedia and Compton's Encyclopedia. I f your plans include winter travel or treks into snowy ranges like the Himalaya in Nepal or Tibet, you need to know how to understand avalanches. You need to be able to recognize the sorts of weather, terrain, and snow that can cause avalanche conditions.
Ice avalanches can be devastating and very dangerous.
Hanging glaciers and glacial seracs calve off. That means they break off unpredictably. An ice avalanche is usually old rubbery ice that falls from a mountain slope or other steep place. Sometimes the ice falls when a glacier is moving. So if you go trekking or are a mountaineer you need to know how to get away from an avalanche, not to make loud noises, and not go on old ice.