IN: Explain the process of saltation. Erosion by Ice 2/4/15 12-3 pgs. 309-315 IN: Explain the process of saltation.

Terms to Learn & Objectives glacier iceberg crevasse glacial drift stratified drift till Objectives: Summarize why glaciers are important agents of erosion and deposition. Explain how ice in a glacier flows. Describe landforms that are deposited and eroded by glaciers.

Glacier – an enormous mass of moving ice.

How do glaciers form?

Glaciers are very heavy which means: They have the ability to move across the Earth’s surface. They are capable of eroding, moving, and deposition large amounts of materials.

Alpine Glaciers Form in mountainous areas. Create U-shaped valleys.

Yosemite Valley

Continental Glacier Huge continuous masses of ice that continue to get larger. Smooth and flatten the landscape. Ice Sheet of Greenland

Ice Shelf An area where the ice is attached to the ice sheet but is resting on open water.

Icebergs – Large pieces of ice that break off an ice shelf and drift into the ocean.

Glaciers on the Move When enough ice builds up on the slope, the ice begins to move downhill. The thickness of the ice and the steepness of the slope determine how fast a glacier will move. An alpine glacier is estimated to be moving forward at 5 meters per day.

As the glacier moves, the rock pieces scrape and polish the surface rock. Larger rocks embedded in the glacier gouge out grooves called striations.

Crevasse – a large crack that forms where the glacier picks up speed or flows over a high point.

Landform Carved by Alpine Glaciers

Cirques are bowl-like depressions where glacier ice cuts back into the mountain walls. Arêtes are jagged ridges that form between two or more cirques cutting into the same mountain.

Horns are pyramid-shaped peaks that form when three or more cirques erode the mountain. Matterhorn, Switzerland

Landforms Carved by Continental Glaciers

Glacial drift – the material carried and deposited by glaciers.

Stratified drift – rock material that has been sorted and deposited in layers by water flowing from the melted ice of a glacier.

Till – unsorted rock material that is deposited directly by glacial ice when it melts.

Moraines are ridges of till that form along the edges of glaciers.

1. Lateral Moraines 2. Ground Moraines 3. Terminal Moraines

OUT: Explain why continental glaciers smooth the landscape and alpine glaciers create a rugged landscape.