Glaciation

Question 1

What are glaciers?

Answer 1

Masses of ice that fill valleys and slowly move downhill.

They can carve up the landscape through erosion.

Question 2

What is the history of glaciers in the UK?

Answer 2

Lots of glacial periods during the last 2.6m years.

During some periods, parts of the UK were covered in a massive ice sheet; All Scotland, Wales, Northern Ireland and Northern England.

The erosion, transport and deposition of material by ice has been important in shaping the landscapes in the UK.

Question 3

How do glaciers erode the landscape as they move?

Answer 3

The weight of the ice moving downhill (known as advancing) erodes in 2 ways:

1) Plucking occurs when meltwater at the base, back and sides freezes onto the rock. As the glacier moves forward it pulls pieces out of the rock.
2) Abrasion is where bits of rock stuck in the glacier grid against the rock below the glacier, wearing it away.

Question 4

How does the top end of a glacier move?

Answer 4

The ice moves in a circular motion, known as rotational slip. This erodes hollows and deepens them into bowl shapes.

Question 5

What is freeze thaw weathering?

Answer 5

This is where water gets into cracks, freezes and expands. If this process is repeatedly the rock eventually breaks away.

Question 6

What are the different landforms produced by glaciation?

Answer 6

1) Arete
2) Corries
3) Ribbon lakes
4) Pyramidal peak
5) Truncated spurs
6) Hanging valleys
7) Glacial troughs

Question 7

What is an arete?

Answer 7

A narrow steep sided ridge formed when two glaciersflow in parallel valleys. The glaciers erode the sides of the valley and this produces the ridge between the glaciers.

An example is Striding Edge in the Lake District. The steep back wall of Red Tarn corrie lake forms part of the arete.

Question 8

What is a corrie?

Answer 8

These begin life as hollows containing a small glacier. As the ice moves the rotational slip erodes the hollw into a steep sided armchair shape. when it melts it can leave a small circular lake called a tarn.

An example is Red Tarn in the Lake District. The erosion has left a deep wide hollow that has been filled with water in the post glacial period

Question 9

What is a ribbon lake?

Answer 9

This is a long thin lake that forms when a glacier retreats. They form in hollows where softer rock erodes more than the surrounding rock.

An example is Lake Windermere in the Lake District and the Scottish Lochs.

Question 10

What is a pyramidal peak?

Answer 10

It’s a pointed mountain peak with a least three sides. It is formed when three or more back to back glaciers erode a mountain.

An example is Mount Snowdon in Wales.

Question 11

What is a truncated spur?

Answer 11

These are cliff like edges on the valley side formed when ridges of land (spurs) that stick out of the main valley are cut off as the glacier moves past.

Question 12

What is a hanging valley?

Answer 12

These are valleys formed by small glaciers that flow into the main glacier. The main glacier is more deeply eroded so when the glaciers melt, the smaller glaciers are left at a higher level.

Question 13

What are glacial troughs?

Answer 13

Steep sided valleys with flat bottoms. They start as V shaped formed by rivers but then become U shaped when the sides and bottom are eroded.

An example is Keswick in the lake District.

Question 14

How glaciers transport and deposit Till?

Answer 14

The material is frozen in the glacier, carried on its surface or pushed (bulldozing) in front of it.

It is deposited when the ice melts, by dropping it on the valley floor. It can make moraines and drumlins.

Deposits are all mixed up together, all sizes and shapes. This is different than a river that sorts.

Sometimes the sand and gravel get washed in front by meltwater streams. The streams sort by size and deposit it in layers (called outwash) in front of the glacier.

Question 15

What are the different types of morraine?

Answer 15

1) Lateral - a long mound of till deposited where the side of the glacier was. Formed when valley walls are eroded and carried along the sides of the glacier.
2) Medial - a long ridge of till deposited along the centre of a valley floor. When two valleys meet the lateral morraines meet and form a line of material.
3) Terminal - builds up at the snout of the glacier. Material that’s abraded and plucked from the valley floor is transported at the front and then deposited as semicircular mounds as the ice retreats.
4) Ground morraine - eroded is dragged along the base of the glacier and is deposited over a wide area on the valley floor as the ice melts.

Question 16

What are drumlins?

Answer 16

These are elongated hills of glacial deposits. The longest ones are 1km long, 1/2km wide and 50m high.

They are round, blunt and steep at the upstream end (back) and tapered pointed and gently sloped at the downstream end (front).

Lots of example in Swindale in the Lake District.

Question 17

What are erratics?

Answer 17

Rocks that have been picked up by a glacier, carried along and then dropped in an area with a different rock type.

They look out of a place; a large boulder on its own.

Examples in the lake District may have travelled as far away as Scotland.

Question 18

Glacial landforms on a map §

Answer 18

See page 61 of the revision guide.

Question 19

What economic uses are glaciated areas?

Answer 19

1) Farming - sheep in upland areas, steep slopes and poor soils are unsuitable for other farming.
- cattle on the flatter valley floors.
- usually too cold for crops; grass is grown to make hay to feed the animals.

2) Forestry - Evergreen forests as they can cope with cold weather in upland areas. Used for timber for building.
3) Quarrying - glacial erosion exposes rock maling it easier to get into. Often quarried for slate, granite and limestone.
4) Tourism - Attractive due to dramatic landscapes. Different activities, hiking, climbing, boating, biking. skiing.

Question 20

How does economic activity cause conflict?

Answer 20

Want to preserve environmental value of attractive areas. But development is needed to provide jobs and to provide roads and facilities.

Question 21

What type of conflict is there?

Answer 21

1) Farming - Grazing sheep removes vegetation. Farmers don’t like tourists walking over their land.
2) Tourism - Infrastructure needed, e.g. tourist centre at top of Snowdon. Damage stone walls, scare sheep, trample crops, leave gates open.
3) Forestry - Chopping trees scares off wildlife. Timber trees are less diverse so supports less variety of animals.
4) Quarrying - Destruction of habitats disturbing wildlife. Makes area less attractive. Need large trucks and roads.

Question 22

What are economic impacts of tourism in glacial areas?

Answer 22

1) Positive impact and normally the main industry.
2) Offers employment to local people although often seasonal and low paid.
3) High house prices due to demand for holiday and second homes. Forces local people out as they can’t afford.
4) Prices of goods and services are often higher as tourists prepared to pay more.

Question 23

What are the social impacts of tourism in glacial areas?

Answer 23

1) Increased traffic, roads often narrow, congestion, lack of parking.
2) Shops tend to be geared up for tourists rather than locals.
3) Holiday homes empty for part of the year. Can lead to reduced services at off peak times of year, e.g buses.

Question 24

What are the environmental impacts of tourism in glacial areas?

Answer 24

1) Footpath erosion due to walkers. Vegetation destroyed, soil erosion.
2) Litter, bonfies, BBQs.
3) Water sports - noise pollution, waves erode shoreline.
4) Tourists may park on grass verges damaging vegetation.
5) Wildlife can be disturbed by walkers and their dogs.§

Question 25

Strategies to cope with tourist impact?

Answer 25

1) Manage footpath erosion - resurface, hard wearing materials, reseed vegetation, signposting, fencing.
2) Manage traffic congestion - more public transport, improve roads, encourage bikes by encouraging discounts, park and ride schemes.
3) Protect wildlife and farming - Use litter signs, covered bins, keeping dogs on lead, responsible tourism.

Question 26

Tourism example in Isle of Arran, Scotland

Answer 26

• Isle of Arran has impressive glacial features that attract tourists from the mainland of Scotland.
• Goatfell Pyramidal peak, 874 metres high.
• A’Chir ridge is a knife edged glacial arete that divides two corries.
• Glacial troughs include Glen Rosa and Glen Sannox.
• Attracts runners, walkers, climbers, abseiling, paragliding.
• Footpath erosion.
• Seasonal weather impacts tourism in winter with little else employment.
• Lot of congestion at popular times.
• Lots of deaths and injuries from climbers.
• Positive impact from 200,000 tourists per year.
• Visitor attractions generate £30m annually.
• Attracts young families who want to mover there.