Glaciers

Glaciers are very important to our life on earth. Humans threaten glaciers with pollution that helps cause global warming. People rarely think of the damage that global warming could cause if the world's glaciers to begin melting. However glacier ice is important to the human population around the world. If the earth were to warm enough to melt all the glaciers the sea level would rise around 200 feet. This new sea level would be high enought to destroy nearly every coastal city in the world. Despited the great damage glacial destruction would cause most people still know little, and care little, about glaciers.

A glacier is an accumulation of ice, air, water, and sediment that forms a large mass. Glaciers move forward under their own weight, moving from tens of feet to thousands of feet per year. A glaicer will occur in conditions in which the melting of snow in the summer isles that the snow that accumulates during the winter. This only happnes in Polar Regions and high mountain areas. Today glacier occupy about 11% of the earth.

Glaciers all being in snowfields. As snowfields grow in thickness, solid ice is formed through gradual re-crystallization of teh accumulated snow. During the intial stage, melting, evaporation, and compaction transform fluffy flakes of newly fallen snow into a porous mass of small, rounded granules called firn.

A glacier polishes the bedrock floor over which is passes. Rocks adn sand particles pushed along by the ice are similar to giant piece of sandpaper on the land. Frost action, landsliding, and avalanching carry rock debris onto a glacier surface from the land above it. The material transported by a glacier ranges from house-sized boulders to clay particles. When the glacier melt, all of this material is left where the melting occurred. The remainining material can greatly change the surface of the land. Most of the land today has been shaped and formed by glaciers. Our glaciers today our remnants of the ice that covered the earth in the ice-age.