Information on Glaciers

     A glacier is compact frozen snow.  Two characteristics are that glaciers are formed form snow and move because of their own weight.  There are three classifications of glaciers.  The first is continental glaciers or ice caps.  The largest ice caps are found in Antarctica and Greenland.  Antarctica is almost completely covered and Greenland is 85% covered.  The next classification is valley glaciers which are found on mountain ranges on every continent. The last classification is piedmont glaciers.  These glaciers form a sheet of ice at the foot of mountain ranges.

      Glaciers form when only some of the snow above the snow line melts in the summer.  Then it refreezes and another layer of snow falls on it.  Then year after year it becomes more and more compact and dense.  This process causes it to change into a granular ice called nv.

      Glaciers move because of gravity.  Sometimes they move on a thin layer of water.  Valley glaciers move faster then continental glaciers

      Water from the glacier goes penetrates the gaps in the rocks.  The water freezes and expands; the rock breaks off, and becomes part of the glacier.  This is called plucking or quarrying.  There are two ways the rock is used.  The first is abrasion, is where the rock acts as a piece of sandpaper.  The second is called bulldozing where the glacier is pushing everything in its way.

      All sediment of glacier erosion is called drift.  The four different types are till, drumlins, glacial erratic, and stratified drift.  As the glacier moves and or melts, it leaves behind rock and rock flour that had become a part of it.

      When a glacier reaches the ocean, it melts and sediment goes to the ocean floor.

     The geology of Antarctica can be found on the internet, at the library, and in encyclopedias.