Gcse Geography - Glaciers

Front 1

What is a Glacier?

Back 1

A glacier is a mass of ice that moves slowly downhill, they're found at high altitude and generally high latitude (close to either the North or South pole).

Front 2

What are the different types of glacial erosion and the differences between these?

Back 2

Glacial erosion is one way in which glaciers shape the landscape, there are three different types:
1) Freeze Thaw Weathering:- This is the action of glacial meltwater on joints, cracks and hollows in rocks. Water gets trapped in these cracks, freezes and expands, when the water thaws the rock is weakened and eventually causes the rock to break up.
2) Plucking:- Rocks and stones become frozen to the base/sides of the glacier. When the glacier moves they are torn from the ground or rock face. It leaves behind a jagged surface.
3) Abrasion:- Rocks being carried by the glacier scrape the rock faces and bedrock acting like sandpaper. This leaves a smooth surface which may have striations (scratches).

Front 3

Corries and their formation
Part One

Back 3

Corries are often the starting point of a glacier. They are formed when snow collects in a hollow, over time more snow falls and compacts, forming a neve. Over thousands of years this will become a glacier and through glacial erosion this hollow will become bigger.

Front 4

Corries and their formation
Part Two

Back 4

The glacier can't move downhill but in a circular motion know as rotational slip. Plucking produces a steep back wall and abrasion deepens the corrie. Some of this debris is deposited at the edge of the corrie forming a corrie lip. When the glacier melts water becomes trapped by the corrie lip. This is called a tarn.

Front 5

What are these key features:
1) A Glacial Trough
2) A Tributary
3) A Hanging Valley
4) Truncated Spurs

Back 5

1) Glaciers cut a distinctive u-shaped valley or glacial trough with a flat base and steep sides.
2) Like rivers glaciers also have tributaries which are smaller glaciers that join onto the main glacier.
3) As the main glacier erodes deeper into the valley it's tributary is left higher up the steep sides. When the glacier retreats this often becomes a waterfall.
4) Interlocking spurs form when a river winds and bends around areas of hard rock, a glacier cuts through these ridges to form truncated spurs.

Front 6

What are these key features:
1) Arete
2) A Pyramidal Peak
3) A Ribbon Lake

Back 6

1) A sharp ridge formed when two corries lie back to back, as these corries are eroded by their glaciers the ridge becomes steeper and narrower.
2) When three or more corries meet and are eroded backward forming a sharp, pointed summit.
3) When the glacier moves over an area of soft and hard rock, the soft rock is less resistant and so is eroded more leaving a lip of hard rock. When the glacier retreats water fills the trough creating a long thin lake.

Front 7

What are these key features:
1) Roches Mountonee
2)Crag and Tail

Back 7

Both are created when the glacier hits an area of resistant rock and is forced to flow over it.
1) Plucking on the far side and abrasion on the other side occur. They often have steep jagged faces.
2) Often larger than a Roches Mountonee, in this case the ice hits the steep resistant rock first which protects the far side from erosion.

Front 8

What are these key features:
1) Erratics
2) Drumlins
3) Eskers
4) Kames

Back 8

1) Unsorted, angular and different size deposits from the glacier.
2) Elongated hills of glacial deposits, often found in groups which can be called a basket of eggs. When the glacier became overloaded with sediment the drumlin will have been deposited. The long axis indicates which way the glacier was travelling.
3) Narrow worm-like ridges made up of unsorted glacial deposits, formed by streams flowing under a often weak glacier.
4) Steep sided mounds of unsorted material. Deposited in a crevasse or hollow in the ice, when the ice retreats the material is dropped in a pile on the floor.

Front 9

Moraine

Back 9

There are four main types of moraine made of piles of glacial deposits:
1) Terminal Moraine:- Marks the furthest point the glacier reached.
2) Lateral Moraine:- Deposited along the sides of the glacier
3) Medial Moraine:- Are formed at a junction between to glaciers.
4) Ground Moraine:- Disorganised piles of rock at the base of the glacier.

Front 10

What are these remaining key features:
1) Boulder Clay/Till
2) Misfit Stream
3) Melt-water
4) Accumulation
5) Ablation

Back 10

1) All materials deposited by ice
2) A river flowing through a glacial trough that clearly didn't create the valley.
3)Water that comes from melted snow or ice.
4) The gaining of snow/ice.
5) The reduction of snow/ice.