Lithosphere - Glaciated Landscapes

Question 1

What is a Glacier?

Answer 1

A Glacier is a slowly moving mass or river of ice formed by the accumulation and compaction of snow on mountains or near the poles.

Question 2

How are Glaciers formed?

Answer 2

Glaciers are formed when snow falls and doesn’t melt, so each year when the snow falls it accumulates, therefore over hundreds of years due to the weight of the snow the deepest snow compacts to become ice. Eventually the weight of the ice becomes to much causing the glacier to move.

Question 3

What is plucking?

Answer 3

The glacier melts due to friction and the water gets into cracks in the rocks on the sides and below the glacier and freezes and as the glacier moves it plucks away large pieces of rock.

Question 4

What is abrasion?

Answer 4

Abrasion is when large rocks trapped under the glacier get dragged along by the glacier, grinding away the ground below. The rocks act like sandpaper

Question 5

What is frost-shattering ?

Answer 5

Frost shattering is when rain water gets into the cracks in rocks and freezes, making the gap wider . This process repeats until eventually the rock breaks into several pieces.

Question 6

What is another name for frost-shattering?

Answer 6

Freeze-thaw action

Question 7

What is the difference between erosion and weathering?

Answer 7

Weathering is the process of breaking up and discolouring rocks while erosion is when those weathered rocks are moved away.

Question 8

What is the Gaelic word for a corrie?

Answer 8

Coire

Question 9

What is the welsh word for a corrie?

Answer 9

Cwm

Question 10

Why is snow more able to build up in North-facing mountain hollows?

Answer 10

North-facing sides of mountains are normally colder as they get less sun

Question 11

What is the specific name given to where the snow builds up in a hollow?

Answer 11

Zone of accumulation

Question 12

What is neve?

Answer 12

Neve is a type of snow that has been partially melted, refrozen and compacted yet precedes the form of ice.

Question 13

What is a Bergschrund crevasse?

Answer 13

Bergschrunds are cracks that appear between the moving ice of a glacier and the non-moving stagnant ice of a mountain or cliff.

Question 14

How is a Bergschrund crevasse formed?

Answer 14

A bergschrund crevasse is formed when the glacier pulls away from the back wall of a corrie leaving a gap.

Question 15

How are Corries Formed?

Answer 15

= SNOW ACCUMULATES in North facing mountain hollows (1) as more snow falls in winter than melts in Summer. (1) This is referred to as the zone of accumulation.
= North facing slopes are more shaded so snow builds up here.(1) Under it’s own weight the snow is COMPRESSED to form NEVE and then to ICE (1) , forming a glacier.
= Due to gravity and irregularities under the glacier it begins to move DOWNHILL AND ROTATES (1) .
=PLUCKING occurs where the glacier freezes into cracks on the back wall and pulls away loose pieces of rock, making the back wall steep. (1)
= ABRASION occurs as sharp rocks trapped under the glacier grind away a bowl-shaped hollow. (1)
= A BERGSCHRUND crevasse is sometimes formed as the main body of the glacier pulls away from the back wall leaving a gap.(1)
= Erosion is less at the front edge of the CORRIE forming a LIP which traps glacial melt water forming a corrie loch or TARN.
= An example of a corrie is Red Tarn Corrie in the Lake District (1)

Question 16

How are Aretes formed?

Answer 16

When two corries form back to back, the steep back walls join to form a steep knife edge ridge. This is called an Arete. The Arete is made more jagged through te process of frost shattering. Striding edge is an example of an arete in the Lake District National Park.

Question 17

How are pyramidal peaks formed?

Answer 17

When three or more corries form back to back a sharp point is created. This is called a pyramidal peak. The pyramidal peak is sharpened further through the process of frost shattering. An example is the Matterhorn in the swiss alps.

Question 18

How are U-shaped Valleys formed?

Answer 18

Before glaciation valleys were V-shaped. Glaciers became too big for corries and, due to gravity, moved downhill in to v-shaped valleys. As the glacier moved down through the v-shaped valley, abrasion deepens the valley and also creates a wide,flat valley floor. Abrasion is when large rocks trapped under the glacier get dragged along by the glacier, grinding away the ground below. Plucking takes place at the sides of the glacier which steepens the valley sides. Plucking is when the glacier freezes into cracks in the rock on the sides and below the glacier and as the glacier moves it plucks away large pieces of rock. Above the glacier Frost-Shattering further steepens the valley sides. The valley is also straightened as interlocking spurs are cut off by the glacier forming Truncated Spurs. When the glacier melts a U-Shaped valley is left, often with a small stream called a misfit stream flowing through it.
= An Example of a U-shaped Valley is Langdale Valley, Lake District

Question 19

How are Hanging Valleys Formed?

Answer 19

A Hanging valley is a small U-Shaped valley which is formed by a smaller Glacier in a tributary valley. A Hanging Valley is left hanging above the main U-shaped Valley and therefore a Waterfall is often found here.

Question 20

How are ribbon lakes formed?

Answer 20

As the glacier moves through its valley it erodes the valley floor (abrasion). Softer rock is more easily eroded than harder rock and so a large hollow is formed in the Valley floor. When the glacier melts the water will fill this hollow to form a ribbon lake. Moraine deposited when the glacier melts acts as a dam to hold the water in the ribbon lake.

Question 21

Name features of Glacial Erosion.

Answer 21

• Corrie
• Arete
• Pyramidal Peak
• U-shaped Valley
• Hanging Valley
• Ribbon Lake

Question 22

Name Features of Glacial Deposition.

Answer 22

• terminal moraine
• drumlin
• esker

Question 23

What is Terminal Moraine?

Answer 23

Terminal Moraine is material deposited at the end of the glacier where the ice melts and releases the material trapped inside the ice.

Question 24

How is terminal moraine formed?

Answer 24

As a glacier moves through a valley it plucks away pieces of rock which are then pushed or carried along by the glacier. Material which is transported and deposited by a glacier is called moraine. When the glacier reaches lower altitudes and when temperature increases the glacier begins to melt. It then deposits moraine at its Snout. This forms a ridge of unsorted material which stretches across the valley floor. This ridge can often act as a dam helping to create a Ribbon Lake. Terminal moraine marks the furthest point that a glacier reaches.

Question 25

How are drumlins formed?

Answer 25

Drumlins are elongated hills made up of unsorted glacial till deposits. Melting glaciers deposit a lot of moraine. Drumlins are formed as the glacier becomes overloaded with debris and deposits it, streamlining the sediment as it flows over it. This mound of moraine is later reshaped by future glaciers to form long elongated hills. The steep side called the stoss faces the ice movement. The gentle slope is called the lee slope. Drumlins often occur in swarms or groups

Question 26

What are fluvioglacial deposits?

Answer 26

Fluvioglacial deposits are deposited by glacial meltwater streams. UNLIKE TILL DEPOSITS

Question 27

How are Eskers Formed?

Answer 27

= Eskers are steep-sided, long winding ridges, made up of coarse sand and gravel (1)
= Meltwater streams flowing along the surface of a glacier pass down underneath the glacier at a MOULIN. The stream then flows in a Sub-Glacial tunnel beneath a melting glacier. The stream carries and deposits sand and gravel, filling up the tunnel. When all the ice melt, a long ridge of sand and gravel is left in the shape of the stream’s tunnel. These long ridges are called eskers which are FluvioGlacial deposits as they are deposited by glacial meltwater streams.

Question 28

Trigger Words for Corries

Answer 28

• North, summer, accumulation, compressed, neve, ice, Gravity, movement, downhill, plucking abrasion, bowl, bergschrund, Frost Shattering, Red Tarn corrie- lake district.

Question 29

Trigger words for Arete

Answer 29

Corries , Knife edge ridge, Arete, Frost shattering , Striding edge

Question 30

Trigger words for Pyramidal peak

Answer 30

Corries, Aretes, three corries, back to back, sharp point, frost shattering.

Question 31

Trigger words for U-shaped valley

Answer 31

before they were V-shaped, too big, corries, gravity, Abrasion, Plucking, steepens, Frost shattering, Straightened, truncated spurs, melt, U-shaped valley left, misfit stream, Langdale valley lake district

Question 32

Trigger words for ribbon lake

Answer 32

Erodes valley floor, soft rock easy erode, hard rock hard erode, glacier melts, large hollw is filled, moraine acts as a dam.