Ice

Question 1

What are glaciers

Answer 1

They are large rivers of ice that move very slowly

Question 2

How do glaciers form

Answer 2

Glaciers form when more snow falls than melts each year, then over many years later upon layer of snow compacts and turns to ice

Question 3

What are the two types of glaciers

Answer 3

Continental glaciers and alpine glaciers

Question 4

What are continental glaciers

Answer 4

They are the polar caps over Antarctica and the Arctic circle. A continental glacier is spread out over a huge area

Question 5

What are alpine glaciers/valley glaciers

Answer 5

They are glaciers which form in places with very cold conditions. They are long and narrow. They form in mountains and flow downhill through mountain river valleys

Question 6

What are the different ways Ice erode

Answer 6

Plucking, abrasion, freeze-thaw

Question 7

What is plucking in ice erosion

Answer 7

Plucking is when meltwater from the glacier freezes around cracked and broken rock. When the ice moves downhill, the rock is plucked from the back wall and dragged away by flowing ice

Question 8

What is abrasion in ice erosion

Answer 8

It is when the rock and stones frozen in the base of glaciers scrape the underlying bed rock.

Question 9

What is freeze thaw in ice erosion

Answer 9

Melt water gets into cracks in the bedrock of the back wall of the glacier. At night the water freezes, expands and causes the rock to widen. Eventually the rock breaks away and falls onto the top of the glacier.

Question 10

What are the different features of erosion by ice

Answer 10

Cirque, Tarn, Arête, pyramid peak, u shaped valley, hanging valley, truncated spurs and ribbon lakes

Question 11

How do cirques form

Answer 11

When a round armchair-shaped hollow is carved out near the top of a mountain when glacial ice pulls away from the back wall and starts moving downhill. It plucks rock from the back wall and abrades the hollow, making it deeper.

Question 12

How do tarns form

Answer 12

When the ice in the cirque melts, it creates a circular lake in the hollow called a tarn

Question 13

How does an arête form

Answer 13

A sharp edged ridge that remains when a cirque forms on opposite sides of the same mountain

Question 14

How does a pyramid peak form

Answer 14

A sharp horn is left behind when glaciers have carved out three or four sides of a mountain

Question 15

How does a u shaped valley form

Answer 15

As a valley glacier flows through a v shaped river valley, it scrapes away the sides of the valley, carving out a u shaped valley with a flat floor and steep sides

Question 16

How do hanging valleys form

Answer 16

Pre existing tributaries and their valleys are eroded away by the glacier, leaving the tributaries and their valleys high up the steep sides of the glacier. Their river flows into the main valley in a waterfall

Question 17

How do truncated Spurs form

Answer 17

Where interlocking Spurs existed previously, the glacier moves through the valley, cutting through these ridges, leaving truncated Spurs.

Question 18

How do ribbon makes form

Answer 18

A long, deep, narrow lake, usually found in the u shaped valley where less resistant rock was eroded by a glacier

Question 19

How do glaciers deposit materials

Answer 19

As glaciers flow, mechanical weathering loosens rocks on the valley walls. These rocks fall onto the glacier. Glaciers can carry rocks of any size, and for many kilometers over many years. Glaciers deposit sediment when they melt. They drop and leave behind whatever was frozen in their ice, water from the melting ice may form lakes or other water features

Question 20

What are some features of deposition by ice

Answer 20

Erratic, moraine, drumlin and esker

Question 21

How do erratics form

Answer 21

Giant rocks carried by glaciers are eventually dropped. These glacial rocks are noticeable because they are huge and usually of a different rock type to the surrounding bedrock

Question 22

How do moraines form

Answer 22

When Sediment is deposited by the glacier when the ice melts. Ground moraine is a layer of sediment left behind by a retreating glacier . End moraine is a low ridge of sediments deposited at the end of a glacier, it marks the greatest distance the glacier advanced

Question 23

How does a drumlin form

Answer 23

A long, low hill of sediment is deposited by a glacier. They often occur groups called drumlin fields. The narrow end of each drumlin points in the direction the glacier was moving when it dropped the sediments.

Question 24

How does an esker form

Answer 24

A winding ridge of sand deposited by a stream of meltwater. Such streams flow underneath a retreating glacier

Question 25

What is a summit

Answer 25

The top of a mountain

Question 26

What is a crevasse

Answer 26

A Deep open crack in a glacier

Question 27

What is glacial erosion

Answer 27

It is erosion caused my moving ice