Glaciation Flashcards
Glacier
A large body of snow and ice that moves downhill under its own weight.
Ice sheets
A large mass of glacial land ice that covers more than 50,000 kilometres squared
Ice cap
Large mass of glacial land ice that covers less than 50,000 kilometres squared. Usually found in mountainous areas.
Valley glaciers
A slow moving ice river confined between valley walls.
Corrie Glaciers
Small glacier high up in a sheltered mountainside
Snow patches
Small area of snow and ice. Usually found in north facing mountain slopes
How are glaciers formed?
Snowflakes fall (10% ice 90% air)
The weight of the upper layers compress
The air in the snow is removed so it becomes harder and more dense.
Snowflakes-granular snow-firn (40% ice 60% air)-glacial ice(90% ice 10% glacier ice.
Accumulation = ablation
Glacier in state of balance/equilibrium
Accumulation more than ablation
Grow and advance
More ablation than accumulation
Shrink/ retreating glacier
Calving
When icebergs fall of the glaciers’ at its snout
Antarctica is an….
Ice sheet which keeps 85% of the world’s ice
The youngest glacier in the world is in…..
North America
The Andes are…..
Melting too quickly
Glaciers in the Himalayas provide….
A huge number of people drinking water
In Europe we can find glaciers in….
The Alps and in Iceland
In Africa we find glaciers in …..
Mount Kilimanjaro (Kenya)
The Greenland ice sheet is …..
10% of the ice in the world
Greenland+Antartica= 95% of the ice in the world
Natural causes of glacial retreat and advance
Sunspot activity: areas of uneven temperatures in the sun surface.
Volcanic activity: releases an ash cloud so some rays can’t pass.
Orbital Changes: the earth’s orbit changes towards and away the sun.
Tectonic plates: set off a complete series of events that change the earth’s climate.
What is an ice age?
Period of the earth’s history when conditions are much colder, deep ice covers much more of the earth’s surface and sea levels are lower.
How do ice cores help us to look at the past?
Long tubes are extracted and the bubbles of ancient air are analysed to show what levels of gas where present in the past.
What has ice cores told us?
That the concentrations of CO2 in the air has been rising slowly.
Hazard
Aspect or an event in physical geography which hinders us or causes us problems. Eg. Avalanches
Resource
Aspect or event in physical geography that helps us. Eg. Glacial tourism
How do people living with glaciers adapt their homes?
Steep roofs so snow falls down
Triple glaze Windows to keep them warm
Build their houses in stilts to keep away from the frozen ground.
How do people living with glaciers adapt their clothing?
They use materials very efficient so at keeping the cold out.
How do people living with glaciers get food?
They use hunting and fishing a lot as they can’t farm the land
How do people living with glaciers adapt their industry?
Using the glaciers as a resource. Eg. Tourism, fishing, skiing etc.
Name two types of glacial erosion and explain
Plucking: rocks and stones freeze and stick to the bottom of the glacier and when the glacier melts a little bit, the stones are deposited.
Abrasion: the stones freeze and stick to the bottom of the glacier which then are scraped along the land which slowly wears it away.
Name the main landforms of glacial erosion and explain
U shaped valleys: glaciers shape the valleys as they advance and leave a straight side and flat bottom valley.
Aretes: thin, knife edges of rock found at the sides of a corrie.
Corries/cirques: spaces between two aretes with a steep back and a deep basin below.
Pyramidal peaks: sharp pointed mountain peaks with three or more aretes and corries.
Rouches moutonnees: resistant rocks at the bottom of a u shaped valley that the glacier couldn’t erode.
