Glaciation Flashcards
What is an ice age
A period when large parts of several continents are covered by ice sheets
When did the last ice age end
About 12,000 years ago
What are glaciers
Huge masses of compacted ice
What causes an ice age
-Earth orbit and axis-this happens of thousands of years
-Earths atmosphere-less CO2 to trap heat, less heat
-Ocean currents-distribute heat. When they change, ice sheets can build up
Process of glacial erosion : Plucking
As the glacier moves, the friction between it and the ground causes the bottom the glacier to melt. This meltwater makes its way into cracks in the rocks underneath the glacier and refreezes around rocks.
As the glacier moves, it plucks the frozen meltwater and rocks and carries them away
Process of glacial erosion : Abrasion
As the glacier moves, the rocks attached to it scratch and scrap the surface rock underneath and on the sides of the valley.this scratch marks are called striations and tells us which way the glacier moved in.
How do glaciers transport their load?
- pushed in front
-carried on top
-rolled along thee sides and underneath
Material that falls through cracks are carried within it
Benefits of glaciation : Agriculture
The boulder clay deposited makes foe very fertile soil suitable from agriculture
Eg Golden Vale in Munster
Benefits of glaciation : Tourism
Beautiful landscapes created by glaciers are tourist attractions. Lakes in glacial areas are often used for fishing and boating. Eg. Gap of Dunloe
Benefits of Glaciation: Hydroelectricity
Glacial lakes provide natural reservoirs for the generation of HEP. Eg Turlougn Hill Co. Wicklow uses water fromm Lough Nahanagan
Benefits of glaciation: Roads
U-shaped valleys provide natural routeways through upland areas. Roads are sometimes built on esker too. Eg. Gap of Dunloe
Benefits of Glaciation: industry
Sand and gravel are take from eskers and used in the construction industry. Glacial lakes provide a water supply for industry and urban areas.
Negatives of glaciation: poor agricultural land in upland areas
Glaciers remove much of the soil cover in uplamd areas, leaving them unsuitable from productive agriculture. Sheep farming and forestry may be the only options for this land
Negatives of glaciation: porous drainage
Glacial deposits such as drumlins can lead to poor drainage causing bogs to develop in some areas
Negatives of glaciation: Flooding
Today’s glaciers and ice caps in the Artic and Antartica are melting very fast causing sea levels to rise. If they continue to rise, lowland coastal areas of Ireland may flood
