Like running water, gravity is the driving force behind all glaciers. The ice moves material from high places and deposits it in low places There are 2 primary types of glaciers: Alpine (Valley) Glacier – These form in mountainous regions where the elevation is high enough to support ice all year round Continental Glacier (Ice Sheet) – These form over large land areas In very high latitudes. There are only 2 that exist in the world today, In Antarctica, and Greenland.

Alpine Glaciers

Alpine Glaciers Permanent snow accumulates when new snow falls on old snow. Alpine Glaciers Like a slow moving river the ice starts sliding down the mountain in the valley between the peaks and ridges When the snow becomes thick enough the bottom layers get compressed into ice

The ice whittles the peaks into sharp points called horns

World’s most famous horn, The Matter Horn in Switzerland

Merging glaciers Medial moraine

After the snow melts, the glaciated mountains look like this

U shaped valley

Steep side of U shaped valley is called a hanging wall

Watch out for these crevasse

Rock on the valley floor gets scratched and polished Fresh surface not scratched

Glacially polished bedrock

More polishing with striations and glacial scratching

The surface of glacier gets dirty in summer

Glacial sediments are always unsorted At the front or leading edge Of the glacier terminal moraine is pushed into a bank of unsorted sediments Glacial sediments are always unsorted

Terminal moraine Outwash plain

Calving occurs where a glacier meets the sea

Icebergs form where chunks of the glacier break off

Some icebergs are as big as a city

Continental Glaciers (Ice sheets)

Great North American Ice sheet 10,000 years ago Today the ice sheet is limited to only Greenland

These are called transported soils Throughout the mid-west and northeast there is much evidence that the region was covered by a mile thick layer of ice only 10,000 years ago Most of the soils here have been scraped from Canada and deposited by the glacier These are called transported soils

As the glacier retreated northward, It left behind much evidence of It’s presence

Drumlin near the Finger Lakes

Drumlin in Wisconsin Which direction is south?

Erratic in Central Park

Glacial Erratic in Yellowstone National park

terminal moraine on north shore of Long Island

Kettle lakes Esker in Wisconsin

Kame

Kame used for Sand and gravel