Glacier
A Glacier is a mass of ice and snow, which is continuously moving to lower ground or, if afloat, continuously spreading. This flowing movement happens due to its weight, which causes the bottom layer of ice to behave plastically, and can as a result, flow from the middle of the ice sheet and move slowly towards the sea.
Glacier
Glaciers have an important effect on the rock beneath them. As the ice flows slowly towards the sea, it grinds up the rock and produces a suspension of fine white or yellowish particles that flow out of the glacier front with the meltwater. This `glacial flour’ runs off into the sea to form sediments. On their way down the valleys, the glaciers may also pick up weathered rock and boulders from the valley sides or outcrops. These together with glacial flour, are often deposited at the end of the glacier as it melts and retreats, forming mounds called moraines. Where there is a seasonal cycle of melt and retreat of the glacier snout, a series of annual moraines may form, providing clear evidence of the rate of retreat.
The biggest glacier in the world is in Antarctica. The Lambert Glacier is 515 km long and over 50 km wide. It moves along at a rate of about 2.5 cm a day.
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