Day #2-Processes That Shape Ocean

Basins and DrainageSection 2.3

ReviewWhat is the lithosphere?

Core (rock) and upper mantle (clay)

The PlanDiscuss glaciers, video clips, newspaper article, and

activity.

I can describe glacial features.

http://uncoveringgeology.com/geoparks/

GlaciersGlaciers are large

moving bodies of ice.

Continental glaciers (or icecaps) are glaciers that cover vast areas of land.

Antarctica is covered by a continental glacier that is about 1 and 1/3 times the area of Alberta!

Where Glaciers are FoundThey are

located wherever snow can collect and survive.

Most are fund in the polar regions.

http://pbs.panda-prod.cdn.s3.amazonaws.com/media/assets/wgbh/ess05/ess05_int_glaciers/01_Where.htm

How Glaciers FormSnow in an area

does not all melt in summer.

Each winter, more snow is added.

The weight of all the snow creates pressure = turns the lower parts of the snow into ice.

http://pbs.panda-prod.cdn.s3.amazonaws.com/media/assets/wgbh/ess05/ess05_int_glaciers/01_Form.htm

Valley GlaciersValley glaciers are

glaciers that form high up in mountain ranges.

Snow and ice build up and then begin to move. These glaciers flow down between the mountains.

These glaciers collect pieces of rock, which drag on the surface and determine the form of the land. http://becuo.com/valley-glacier

The Athabasca Glacier

Glacial MovementGlaciers move by

internal changes due to pressure or stress and slide at the base.

The ice in the middle of a glacier flows faster than the ice along the sides of a glacier.

https://www.asf.alaska.edu/blog/how-do-glaciers-move/

Glacial MovementThe movement of glaciers depends on the

climate. Cooler = little melting, snow builds up. The

glacier is said to be advancing (moves forward).

Warmer = more melting, snow melts. The glacier is said to be retreating (moves backward).

Glaciers always flow downhill.

Western Canada Could Lose 70% of its Glaciers by Century’s End!

http://www.edmontonjournal.com/news/edmonton/Western+Canada+could+lose+cent+glaciers+century+study/10949122/story.html

Ice AgesToday we have few continental and valley

glaciers that cover the Earth.

In the past, large areas of the Earth were covered with glaciers. This was the time of the Ice Ages.

The Ice Ages shaped most of Canada’s geography.

http://io9.com/everything-you-need-to-know-about-the-five-ice-ages-of-471281603

Glacial Features

1. Moraines

2. Eskers

3. Drumlins

4. Kettle lakes

As glaciers advance and retreat, they leave many structures:

MorainesMoraines form from rocks

and sediment carried down and deposited by a glacier.

Builds up along the sides and at the end of a glacier.

As the edges of the glacier melt, large deposits form. http://www.landforms.eu/cairngorms/moraine.htm

EskersEskers are long ridges of

gravel and other sediment, deposited by melt water from a retreating glacier or ice sheet.

Typically in the pattern of a winding river.

http://basementgeographer.com/eskers-rivers-of-rock/

DrumlinsDrumlins are small hills with a distinctive

teardrop shape.

They form when a glacier moves over moraines that had formed earlier.

The tip of the drumlin points in the direction that the glacier was moving.

Kettle LakesKettle lakes are lakes formed when large

chunks of ice left behind by the glacier melted away.

The action of glaciers make depressions in the land.

How Glaciers Shape the Land

…and after a glacierDuring