Glaciers are made of solid ice flowing under pressure, flowing fastest at the top, midway between the sides, where it is furthest from any frictional effects.
The earth has experienced a series of Ice Ages, detectable today because glacial erosion creates very distinctive landforms which indicate past history.
The most obvious glacial landforms are moraines, cirques, drumlins, hanging valleys and 'erratics', which remain long after the glaciers are gone.
One of the best indications of past glaciation comes from wide U-shaped valleys, quite unlike the V-shaped valleys made by flowing water in streams and rivers.
As a Swiss, Louis Agassiz saw plenty of glaciers, and in 1839, he had discovered that a cabin, built on a glacier in 1827, had moved about 1.5 kilometres.
Louis Agassiz drove a straight line of stakes into a glacier, and found they moved into a U shape as the ice flowed faster in the centre than on the edges.
Glaciers transport sediment and also create it by grinding the base of the valley with the rocks they drag over the lower surface, producing 'rock flour'.
Varved shales form when there is a regular seasonal variation in stream flow with summer flows being greater than winter flows, as in glacial outflows.
At the moment, glaciers are melting, all over the world, which may mean summer droughts in areas reliant on the release of summer meltwater, like India.
This file is http://members.ozemail.com.au/~macinnis/scifun/splatsglaciat.htm, first created on February 16, 2008. Last recorded revision (well I get lazy and forget sometimes!) was on February 16, 2008.