Guided Notes For Glaciers Section 8.3

Glaciers shape the landscape by eroding, transporting, and depositing huge volumes of rock and sediment.

Glaciers form when cold temperatures keep fallen snow from completely melting, and each year, more snow accumulates in an area called a snowfield. The total thickness of the snow layer increases year by year and a glacier begins to form. The weight of the accumulated snow causes enough pressure to force the accumulated snow to recrystallize into ice.

Valley Glaciers Valley glaciers are glaciers that form in high, mountainous areas. The movement of a valley glacier occurs when the growing ice mass becomes too heavy to maintain its rigid shape and begins to flow like a thick liquid. As valley glaciers flow downslope, they carve V-shaped stream valleys into U-shaped glacial valleys.

Continental Glaciers Continental glaciers cover broad, continent-sized areas. They form under the same climatic conditions as valley glaciers, but move in a different way. They are thickest at the center. They are also called ice sheets.

There are 4 landscape features caused by glacial erosion: 1. Cirques: deep depressions scooped out by a glacier.

There are 4 landscape features caused by glacial erosion: 2. Arêtes: where two cirques on opposite sides of a valley meet, they form a sharp, steep ridge called an arête.

There are 4 landscape features caused by glacial erosion: 3. Horns: if there are glaciers on 3 or more sides of a mountaintop, a steep, pyramid-shaped peak called a horn will form.

There are 4 landscape features caused by glacial erosion: 4. Hanging Valleys: a tributary valley that enters a U-shaped valley from high up a mountainside is called a hanging valley

Several landscape features are caused by glacial deposition: 1. Moraines: ridges consisting of till, the mixed debris deposited by glaciers.

Several landscape features are caused by glacial deposition: 2. Outwash plains: The area at the leading edge of a melting glacier, where the meltwater streams flow and deposit outwash is called an outwash plain.

Several landscape features are caused by glacial deposition: 3. Kettle lakes: formed when a large block of ice breaks off a glacier and is covered with sediment. After the ice melts, the depression left by the glacier fills with water and forms what is called a kettle lake.