Ice Age Flashcards
What percentage of the worlds surface was covered in ice.
38 %
When did the last one end in Britain ?
10,000 years ago
What is a glacier
A glacier is a large river of ice they move slowly downhill and Chang the shape of the land by erosion and deposition
Describe where and how glaciers form ?
Glaciers form in very cold places lots of snow falls but not all of it melts. This means that lots of different layers of snow lie on top of each other.
Name any glacier you have studied, and state which mountain range it is found in.
MER DE GLACÉ and the Alps
What is a corrie
Steep sided armchair hollow at the head of a glaciated valley
Anagrams
Plucking abrasion
Explain how a u shaped valley was formed
The glacier erodes the sides and bottom very quickly some of the processes used are plucking freeze thaw shattering, abrasion wearing away the sides and plucking taking out the rocks as they move along the valley.
Switzerland
Pyramidal peak
Define pyramidal peak
Form when 3 or more carries from around a mountain cu back to leaf a horn or peak
What are striations
Striations are grooves or lines that have been left by a glacier.
What do striations tell us
What direction the glacier moves
Name a lowland glacial deposition
Drumlins
What name is given to the time when large parts of the earth were covered in ice.
Ice age or glacial periods.
What is an ice berg
Icebergs are a large floating mass of ice detached from a glacier or ice sheet and carried out to sea.
Where do icebergs come from ?
Icebergs come from glaciers
Where did the ice come from ?
The ice came from the Scandinavian ice sheet
When did the ice age begin
Nearly 2 million years ago
Ice advances are called ?
Glaciations the last one began 70,000 years ago and ended 10,000
What are warm periods between the glaciation periods called
Interglacial periods
What caused the ice age
Scientists are still not sure but suggest it may have been due to variations in the Suns temperature, changes in the earths orbit so that for certain periods we were further from the sun
What is a glacier
A glacier is a large river of ice they move slowly down hill and change the shape of the land by erosion and deposition.
Where do glaciers form ?
Glaciers from in very cold places. Lots of snow falls but not all of it melts. This means that lots of different layers of snow lie on top of each other
How a glacier is made ?
As snow build up, the lowest layers are compacted into ice and this gradually moves down slope under the force of gravity.
What is an ice sheet
Masses of ice which cover large areas of a continent.
What is a valley glacier
Masses of ice which cover large mountain valleys
What is an ice cap
Ice caps are extensive sheets of ice. Technically they cover an area that is smaller than 50,000 km squared, anything bigger is called an ice sheet
Facts about the MER De Glacé ?
The Mer de Glace is 7km long, 1200 metres wide and up to 200 metres thick. Ice moves within the the glacier at a speed of 70 metres a year.
Inputs for a Glacier System
Avalanches but mainly from precipitation of snow.
Output of a glacier
Meltwater with some evaporation
The highest point where the snow falls and turns to ice ?
The accumulation zone
As the glacier moves down hill it starts to warm up and mot this place is known as the ?
Ablation zone
