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.

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.
1) Freeze Thaw Weathering:- charges at ice with angular boulders which help it wear away.
2) Plucking:- ice sticking to the back wall pulls away blocks of rock as the glacier moves..
3) Abrasion:-loose rocks obtained by freeze-thaw and plucking are embedded in the ice, scraping out the bottom hollow.

Front 3

Corries and their formation
Part One

Back 3

Corries are armchair-shaped hollows. over time more snow falls and compacts, forming a neve. freeze-thaw charges the ice with angular boulders wearing away the rock.freeze thaw,water seeps into rock cracks,freezes and expands (9%) putting pressure on rock, over time rock breaks into angular pieces.

Front 4

Corries and their formation
Part Two

Back 4

plucking, ice sticking to the back wall pulls away blocks of rock as the glacier moves.loose rock obtained by freeze-thaw and plucking are embedded in the ice, scraping out the bottom hollow (abrasion).under its own weight the ice begins to move called rotational slip movement.at the front of the corrie there is less erosion and a rock lip is formed.

Front 5

What are these key features:
1) A Glacial Trough

Back 5

1) Glacial trough is a straight trench like valley with a wide,flat floor and steep sides.glaciers move downhill and take the easiest route.unlike a river,it fills the entire valley and their power to erode is much greater.the glacier carves its way straight through the rock,the valley is made deeper and wider by plucking and abrasion.the glacier melts and the v-shaped valley has changed into a u-shaped valley.old interlocking spurs have been cut off to make truncated spurs,old tributaries are left hanging high upon the valley sides so they're called hanging valleys.

Front 6

What are these key features:
1) Arete

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.

Front 7

2) Drumlins

Back 7

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.

Front 8

What are these key features:
1) Erratics

Back 8

1) Unsorted, angular and different size deposits from the glacier.

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.

Front 11

2) A Tributary

Back 11

2) Like rivers glaciers also have tributaries which are smaller glaciers that join onto the main glacier

Front 12

2) A Pyramidal Peak

Back 12

2) When three or more corries meet and are eroded backward forming a sharp, pointed summit.

Front 13

3) A Ribbon Lake

Back 13

.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 14

3) A Hanging Valley

Back 14

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

Front 15

4) Truncated Spur

Back 15

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.