Glaciation Flashcards
What is a cold environment?
Cold environments ( both tundra and polar) are found in high latitude and mountainous regions of the world.They have an extreme climate and unique characteristics such as soil type and the plants and animals found there.
Where are cold environments found around the world?
High latitude environments …sunlight is thin
Altitude ..alpine environments found at high altitude eg Alps, Himalayas, Rockies, Andes
Northern Russia, Greenland, Northern Canada and Antarctica (polar)
How do glaciers form?
A glacier is a system. A series of input, processes and outputs… a glacial budget.
What is the zone of accumulation?
This is where snow is added. Normally at the start of a galcier in a highland area. As more and more snow is added, it is compacted so it forms ice.
How do galciers move?
Ice moves downhill due to the force of gravity.
What is the zone of ablation?
Near the end, or snout, of the glacier ice may melt.
This is the zone of ablation where the glacier may retreat uphill.
What are the processes of erosion?
Glaciers erode landscape as they move downhill through plucking, abrasion and freeze thaw weathering.
What is plucking?
Meltwater freezes on a piece of rock, as the glacier moves, the rock which is embedded is pulled away.
What is abrasion?
Bits of rock which are embedded in the ice from plucking freeze thaw weathering scrape and grind against the rock at the base and sides of the glacier wearing it away.
What is freeze thaw weathering?
When water in rocks freezes and expands, breaking the rock apart.
How are corries formed?
Snow gathers in a north facing hollow. It compresses turning to firn then ice.
The glacier moves downhill due to gravity, eroding as it goes.
Rocks are plucked from the back wall and are embedded in the glacier.
Glacier abrades ( scrapes away) a deep hollow using the material.
Freeze thaw may also occur.
A deep hollow ( corrie) is left often with a tarn ( circular lake)
What are the features of corries?
Arm chair shape ( 3 steep sides)
Steep backwall
Deep tarn
Rock lip
What is an arret?
A jagged ridge, which is formed when 2 corries lie side by side.
What is a pyramidal peak?
When 3 or more corries are formed back to back.
U shaped valleys
As glaciers move downhill they change V shaped valleys into U shaped valleys or glacial troughs.
The ice has great erosive power and removes any obstacles. Glaciers fill the valley and create steep sides and wide bases.
