Glaciers Flashcards
How does a U-Shaped valley form?
it develops in a V-shaped valley where the ice from the glacier erodes the rock around to create a U-shaped valley.
How does an Arete form?
2 corries being eroded further and further backwards against each other to form a knife like edge.
How does a Pyramidal Peak form?
The back walls of 3 or more corries being pushed back to form a very steep, sloped peak.
How does a Ribbon Lake form?
The glacier finds it difficult to erode the hard rock on either side so it only erodes the soft rock creating a rock basin where after the glacier has melted the water fills up. The water is dammed by a rock bar of hard rock at the end of the lake.
What is an Erratic?
A rock or boulder that is different than the surrounding rock and is believed to have been transported a long distance by glacial action.
What is a Drumlin?
Shaped like the back of a spoon. Another sign the glaciers shaped the landscape. It is a mound of deposited moraine the glaciers left behind.
What is Moraine?
Rocks and sediment that has been built up at the bottom of the glacier and then left there when the glacier melts.
What is Erosion?
Wearing away of the rock at the surface.
What is Weathering?
Breaking down of material by the action of the weather.
What is Transportation?
The movement of material from one place to another.
What is Deposition?
Putting down of material somewhere else.
How does a corrie form?
Before Glaciation:
Snow begins to collect in a hollow in a mountain. Over time the snow begins to compress and form layers. Then the bottom of the glacier starts to melt because of the amount of snow above it and because it is at a slight angle the glacier moves in a way called rotational slip.
How does a corrie form?
During Glaciation:
Freeze thaw weathering and Plucking deepens the back wall. Abrasion deepens the hollow.
How does a corrie form?
After Glaciation:
When the glacier melts. It drops all the rocks and debris creating a rock lip and moraine at the top of it keeping the melted water in the hollow. We call the a Tarn or in Scotland a Lochan. Freeze thaw weathering also creates a scree slope on the back wall
