Glaciation of Canada

Identify a evidence of earth-shaping forces and processes Learning goals: Further your knowledge and understanding of earth-shaping forces and processes Identify a evidence of earth-shaping forces and processes

WHAT IS A GLACIER? WHAT IS A GLACIER? WHAT IS A GLACIER? - a large section of ice and snow that moves across the land, shaping and changing it - doesn’t melt completely in the warmer months HOW IS A GLACIER MADE? HOW IS A GLACIER MADE? HOW IS A GLACIER MADE? - layers of snow and ice pile up over time - the pressure and weight compact the ice and snow and make it heavy

Because of its hardness and heaviness, ice has the power to transform the shape of the land. Glaciers have made such a visible impact on the Canadian landscape because glaciation occurred recently in Canada

Glaciers advanced across Canada four separate times in the last 2 Glaciers advanced across Canada four separate times in the last 2.5 million years. After each advance, the glaciers melted and ‘retreated’ The first three glacial advances are not important in Canada today because the fourth one erased most evidence of them. Glaciers still exist in a few mountainous areas of Canada

Alpine Glaciers - found in valleys in mountainous regions

Continental Glaciers - occupy large areas of land and move under their own weight

As a glacier moves across the landscape, the pressure and weight of the snow creates large cuts in the rock it moves over called striations. A simple analogy: envision the large rocks a glacier carries as chisels, gashing and scraping out new formations in the ground below.

A U-Shaped Valley formed as a glacier cut through this area. It started out V-Shaped.

till is the material that gets scraped off the land and is carried by a glacier. Till creates many different depositional landforms

Drumlins Elongated hills shaped like inverted spoons or half-buried eggs, formed by glacial ice acting on underlying till. There are often several in an area, called a drumlin field.

Eskers long, winding ridges of sand and gravel. They are often several kilometres long

One looooong esker! Uppsalaåsen esker, in Sweden, stretches 250km and passes through a city

These “misfit” rocks are called erratics. A glacier can pick up small and large pieces of the Earth’s surface and drop them in areas that seem odd. These “misfit” rocks are called erratics.

More erratics.

After the ice of glaciers melted when the temperatures warmed up, the meltwater filled in any depressions made from erosion. Creating glacial lakes all across the landscape.

More glacial lakes.

The Creation of the Great Lakes

Glacier

Which glacial landform is this?

Esker

Striations

Erratic

U-shaped Valley

Drumlin Field