Glaciation Flashcards
Periods of ice advantages (ice ages) are called?
Glaciations
Warm periods between Glaciations are called?
Interglacial periods
What is a glacier?
A mass of moving ice
Today glaciers cover
1/10 of the worlds surface
High latitude means
The glaciers are closer to the poles and further away from the equator.
High altitude means
Glaciers away from the poles. This type of glacier only exists in mountainous terrain. As long as the mountain is high enough there will even be glaciers close the the equator.
How does a glacier form?
- Snowflakes collect or accumulate in a hollow or in a mountain side.
- More and more snow falls on the flakes increasing the density or weight.
- The increased weight compresses the snow at the bottom into solid ice.
- If the ice does not melt and the snow continues to fall, the ice mass (glacier) will become bigger and heavier. Gravity will cause it to go downhill very slowly.
Advancement means
Accumulation > melting
Glacier retreat means
When more snow melts than falls (ie abrasion) is higher than ablation so the glacier grows.
Frost shattering/freeze they weathering is
A process of erosion where glacial ice freezes onto rocks and, as it moves away, pulls large pieces of rock with it.
How much of the earth’s surface was covered in ice during the last ice age?
30%
Corries or cirques are
Large bowl-shaped hollows in mountainous areas, snow builds up here so they are generally the source of ice for glaciers
An arête is
A narrow knife-edged ridge on the mountain top. Generally form around a corrie.
A pyramidal peak is
When 3 or more corries cut back into the same mountain they leave a pyramidal peak
Moraine is
A type of landform that is created when a glacier deposits the material (fill) that it has been transporting. It is made up of unsorted angular rocks. There are several types of moraine.
