Glacial Processes Flashcards
Glaciers
Masses of ice that fill valleys and hollows
As they make there way downhill, they shape their surroundings through erosion and through transportation and deposition
How do glaciers move downhill
Weight of the ice in glaciers makes them move down hill
Some glaciers have thin layer of meltwater that acts as lubricant, helping glacier move by a process called basal sliding
Glaciers erode the landscape in which 2 ways
Abrasion- bits of rock stuck in the ice grind against the rock below the glacier, wearing it away
Plucking- meltwater at the base, back or sides of a glacier freezes onto rock. As the glacier moves forward it pulls out pieces of rock
What is rotational slip
At the top of the glacier, the ice doesn’t move in a straight line- it moves in a circular motion ( rotational slip)
What is freeze thaw weathering
The rock above glaciers is broken down by water gets into cracks in rock?
The water freezes and expands, putting pressure on the rock. This ice thaws and releases pressure. If this process is repeated and it can weaken rock
How does glaciers transport material
Transportation- Glaciers move material (sand clay and rocks) over large distances.
What is bulldozing
Transported material is frozen in the glacier, carried on its surface or pushed in front of it. When glaciers push loose material ahead of them this is bulldozing
Deposition
Glacier is overloaded with material Or when ice melts. This material is deposited, forming moraines and drumlins
Meltwater streams
Find materials such as sand and gravel can get washed away from the front of the glacier by small melt water streams.
These sort the material by size and deposit it in layers (outwash)
Where are most glaciers located in the uk
No glaciers in the uk
Most of the uks upland areas have been affected by ice at some points in the past.
When was most of the uk covered in ice
Over 2.6 million years
What is an arête
Narrow steep sided ridge formed when two glaciers flow in parallel valleys
Glaciers erode this sides and sharpen the ridge between them and giving a jagged profile
Pyramidal peak
Pointed mountain peak with at least three sides its formed when three or more back to back glaciers erode a mountain
Example of an arête
Striding edge, Lake District
Example of a pyramidal peak
Mount snowdon
What are corries
Hollows containing a small glacier
As rotational slip takes place, the hollow is eroded into a steep sided shape
When ice melts, it can leave a small circular lake called a yarn
What are corries
Hollows containing a small glacier
As rotational slip takes place, the hollow is eroded into a steep sided shape
When ice melts, it can leave a small circular lake called a yarn
Example of a tarn and corrie
Red tarn, Lake District
Ribbon lakes
Long thin lakes that form after a glacier retreats
Form in hollows where the softer rock was eroded more than the harder rock
Example of a ribbon lake
Lake Windermere
What are truncated spurs
Cliff like edges on the valley side formed when spurs are cut off as glacier moves past
Hanging valleys
Valleys formed by small tributary glaciers that flow into a main glacier
The glacial trough of the larger glacier is eroded more deeply, so when all of the glaciers melt- the tributary glaciers valleys are left at a higher level
Lateral moraine
Long amount of material deposited where the side of a glacier was.
It’s formed of lateral material eroded from the valley walls and carried along the surface ice at the sides of a glacier
Medial moraine
Long ridge of material deposited along the centre of a valley floor
When two glaciers meet, the lateral moraines collide and form a line of material running along the centre of the new glacier
Terminal moraine
Builds up at the snout of a new glacier- it marks the furthest point by the ice
Material that’s abraded and plucked from the valley floor and transported at the front of the glaciers
Ground moraines
Eroded material that was dragged along the base of a glacier
It is deposited over a wide area on the valley floor when the ice melts
Drumlins
Elongated hills thought to be formed when melting glaciers deposit material.
This material builds up over time,forming hills beneath the glaciers
Round and steep at the uphill end. Tapered pointed and gently sloping at the downstream end.
Erratics
Rocks that have been picked up by a glacier, carried along and dropped in an area with a different type of rock
Erratics look out of place
Economic uses of glacieted areas - farming
Sheep farming is common in upland general areas, because steep sloping and poor fertile soils make it unsuitable for other farming
Crops can grow at lower altitudes e.g grass grown on valley floo used for cattle farming
Quarrying
Glacial erosion has left lots of rock exposed, making it easier to access
Glacial landscapes are quarried for slate and limestone ( construction)
Tourism
Glaciated areas have dramatic landscape, making them attractive tourists hotspots
Many activities to do- hiking, climbing, boating cycling and skiing
Foresty
Coniferous forests can cope with the cold weather and high rainfall, so are often planted in upland glacial areas
These trees can easily be used for building materials paper and furniture
Conflict of glaciated landscapes- tourism
Tourists can distrust farming by damaging property - by leaving gates open and tramplijg crops
Conflicts in glacial landscapes
Local residents may object to the noise of a quarry and the frequent passing of large trucks
Quarries can create eyesores for tourists, so fewer tourists come and spend money
Development conflict with conservation in glacial areas
Conservationists want to preserve the environment but development is needed to provide employment l, roads and facilities.
F
Lake District as a glaciated area
Cumbria
Attracts 19.2 million visitors per year
Reason for tourism’s in the Lake District
Scenery- large lakes and mountains Windermere, scaffel pike
Cultural attractions- the Wordsworth museum and Beatrix potters house
Activities-
Water sports, bird watching, hiking, fishing, mountain biking.
Environment impacts on tourism
Large number of hikers using main footpath on cat bells mountain, causing erosion
Tourists park on grass verges in langdale valley- damaging vegetation
Noise and water pollution caused by boats and water sports on Windermere lake
Economic impacts of tourism
Tourism employed over 18000 per year and made 1.5 billion pounds that goes to support local business and economy
However this is only seasonal especially during the summer
Average house price is 350 thousand but the local residents average income is 20000 so they cannot afford to live here
Social impacts
83% if visitors travel by car. Traffic is heavy on the roads linking national with the motorway.
Businesses in villages cater for tourists so prices are higher and less shops
Almost 25% of properties in Lake District are second homed or holiday homes. Fewer people live in the national park all year so many business have close like schools and buses,
Management strategies
Strategies are being put in place to tackle problems caused by tourism
