GLACIATION

About 15 million square kilometres of the earth’s surface are currently covered with glaciers

Continental ice sheets

Two Types of Glaciers Continental: found at high LATITUDES ex. Greenland, AntarcticaContinental: found at high LATITUDES ex. Greenland, Antarctica Alpine: found at high ALTITUDES ex. Western CordilleraAlpine: found at high ALTITUDES ex. Western Cordillera

How GLACIERS Form Two conditions need to be present: 1. Prolonged cold 2. Accumulation of snow Over time, the overlying snow layers of snow compress the lower layers until it becomes ice.

How Do Glaciers MOVE? Glaciers move like a very thick liquid Depending on the climate, a glacier can do one of three things: –Advance –Stay Stationary –Retreat Mass Balance: the rate of accumulation is balanced by the rate of ablation (melting)

How Do Glaciers Alter the Landscape? Glaciers leave evidence on the landscape in the form of erosional features: –Striations –U-shaped Valleys –Spillways –Misfit Streams

Depositional Features 1. Ice Deposits –Till –Moraines –Drumlins –Erratics 2. Meltwater Deposits – Eskers – Outwash plains

A Moraine

Oak Ridges Moraine

Spillway with a Mistfit stream

V- Shaped Valley

U-Shaped Valley

How ice alters the landscape 1.scraps or scours - like sandpaper - rocks are embedded into the bottom of the ice sheet and erode the bedrock as it flows 2.conveyor belt - embedded rocks are carried in the ice and deposited in the front as the glacier flows 3.plucking - ice freezes onto the rock and pulls or plucks it away as it flows 4.bulldozer - material is pushed along in front

The End!