Frozen Planet Flashcards
What is a cold environment?
Areas of land permanently covered by ice. They are covered by glaciers, ice sheets and have frozen soil/rock. The temperature is constantly below freezing.
Where are cold environments found globally - latitude?
The further away from the equator the colder the temperature as the earth is curved. This is latitude. Sun has to pass a greater distance to reach earth from north and south poles so energy is lost. Also snow reflects the sun.
Where are cold environments found globally - altitude?
Higher altitude have colder temperatures (temp reduces 1 degree every 100 metres). Sun heats land, land heats air above it and less pressure means less heat.
Where are cold environments found globally - continentality?
Sea takes a longer time to heat up compared to land but the sea retains heat longer. Places in the middle of continents will be colder in winter and warmer in summer.
What is a glacier?
A glacier is a huge mass of ice that moves slowly over land. It forms when there is a build up of snow and can be found at altitude or sea level. They are known as rivers of ice.
What does a glacier deposit as it moves down the hill?
Ice, meltwater and sediment
What are the two zones of a glacier? Why do glaciers grow and shrink?
Accumulation zone and Ablation zone.
What is an accumulation zone?
inputs (fresh snow and ice)into the glacial budget.
What is the ablation zone?
Meltwater and calving are outputs from the glacial budget.
What are differents types of glacial erosion?
Plucking, abrasion and freeze thaw
What is plucking?
When meltwater at the base of the glacier freezes on the rock surface. As the glacier moves forward it extracts pieces of the rock surface leaving jagged rock.
What is abrasion?
Rock fragments in the ice grind against the rock over which the ice is moving and wears away the land. Smooth like sand paper or stripey (striations)
What is freeze thaw?
This is a type of weathering. Water in cracks freezes and expands. This puts pressure in the surrounding rock. As it thaws, pressure is released. It repeats and rocks break away. Scree is where loose bits of rock break away.
What is a glacial budget.?
Describes how ice accumulates and melts on a glacier which ultimately determines whether a glacier advances or retreats.
Input - snow building up which gets compacted
Process - gravityand weight moves the glacier downhill which takes sediments and erodes
Output - scree/ sediment, meltwater , ice
Why does a small glacier eventually form?
Why is back wall very steep?
How does glacier move?
How is hollow deepened?
Why does a lip form?
Ice melted that forms what?