Glacial Landscapes in the UK
Glacial Erosion
Much of the UK used to be covered in ice
Glaciers erode the landscape
Lots of glacial (cold) periods during the last 2.6 million years
During some glacial periods, parts of UK covered in massive ice sheet
Ice covered most of Scotland, Ireland and Wales and came as far south as the Bristol channel in England
Weight of ice in glacier makes it move downhill
Moving ice erodes landscape in two ways
Plucking - meltwater at base, back or sides of a glacier freezes onto the rock, as it moves forward it pulls pieces of rock out
Abrasion - bits of rock stuck in ice grind against the rock below the glacier wearing it away
At top end of the glacier the ice moves in a circular motion called a rotational slip, this can erode hollows in the landscape
Rock above glaciers is also weathered by the conditions around glaciers
Freeze-thaw weathering is where water gets into cracks in rocks
Glacial Landfiorms
Products of glacial erosion
Glaciers transport and deposit material called till
Arête is a narrow, steep-sided ridge formed when two glaciers flow in parallel valleys. The glaciers erode the sides of the valleys, which sharpens the ridge between them giving it a jagged profile
Pyramidal peak is a pointed mountain peak with at least three sides - formed when three or more back-to-back glaciers erode a mountain
Corries begin as hollows containing a small glacier, as the ice moves by rotational slip, it erodes the hollow into a steep-sided armchair shape with a lip at the bottom end
Ribbon lakes are long, thin lakes that form after a glacier retreats. They form in hollows where softer rock was eroded more than the surrounding hard rock
Glacial troughs are steep-sided valleys with flat bottoms. They start off as a V-shaped river valley but change to a U-shape as the glacier erodes the sides and bottom, making it deeper and wider
Hanging valleys are valleys formed by smaller glaciers (tributary glaciers) that flow into the main glacier, the glacial trough is eroded much more deeply by the larger glacier so the valleys are at a higher level
Truncated spurs are cliff-like edges on the valley side formed when ridges of land (spurs) that stick out into the main valley are cut off as the glacier moves past
Glaciers can move material over very large distances - transportation. This material is called till
The material is frozen in the glacier, carried on the surface or pushed in front of it - its called bulldozing when the ice pushes loose material in front of it
When the ice carrying the material melts, the material is deposited on the valley floor, forming landforms such as moraines and drumlins
Most glacial deposits aren't sorted by size and weight like river deposits - rocks of all shapes and sizes are mixed up
However, very fine material can get washed away from the front of the glacier by small meltwater streams - the streams sort the material by size and deposit it in layers (called outwash) in front of the glacier
Glacial Deposition
Moraines
Drumlins
Erratics
Lateral moraine is a long mound of material deposited where the side of the glacier was - formed by material eroded from the valley walls and carried along the ice surface at the sides of the glacier
Medial moraine is a long ridge of material deposited along the centre of a valley floor, when two glaciers meet, the lateral moraines from the two edges join and form a line of material running along the centre of the new glacier
Terminal moraine builds up at the snout of the glacier - marking the furthest point reached by the ice. Material that's abraded and plucked from the valley floor is transported at the front of the glacier
Ground moraine is eroded material that was dragged along the base of the glacier and is deposited over a wide area on the valley floor as the ice melts
Elongated hills of glacial deposits - can be over 1000m long, 500m wide and 50m high
Round, blunt and steep at the upstream end, and tapered, pointed and gently sloping at the downstream end
Rocks that have been picked up by a glacier, carried along and dropped in an area that has a completely different rock type
Identifying Glacial Landforms
Pyramidal peaks, corries and arêtes
Corries
Corries have tightly packed contours in a U-shape around them
Pyramidal peak
Arêtes
Some have a tarn in them
Tightly packed contour lines that curve away from a central high point
Very thin hill with tightly packed, parallel contours on either side
Corries or tarns on either side, and footpaths on them
Glacial troughs and ribbon lakes
Glacial trough
Flat valleys with very steep sides - no contour lines on bottom of valley but tightly packed at side
Wide straight valley in a mountainous area with a river that looks too small to have formed a valley
Ribbon lakes
Many glacial troughs have ribbon lakes in them - flat valley with steep sides surrounding a long straight lake
UK Glacial Landscape
Snowdonia - glacial landscape in North Wales
Upland areas of Snowdonia show many landforms
Sharp ridge between two corries, known as Y Gribin, example of an arête, at lower end it is cut off by the Ogwen valley - leaving a truncated spur
Llyn Bochlwyd and Llyn Idwal are tarns - sit in hollowed our corries above main valley
Llyn Ogwen is a ribbon lake
Nant Ffrancon is a glacial trough, you can see the large U-shaped valley and the River Ogwen that looks too small to have created it
A lot of moraine can be found around Llyn Idwal, where it was deposited by the melting glacier
Land Use in Glacial Landscapes
Economic Uses
Conflict caused by economic activity
Farming
Sheep
Grass to make hay
Forestry
Coniferous forests planted in upland areas because they can cope
Quarrying
Erosion leaves lots of rock exposed
Tourism
Glaciated areas have dramatic landscapes
Variety of activities
Farming
Forestry
Quarrying
Tourism
Sheep remove vegetation from landscape
Some farmers don't want tourists to walk though land
Chopping forests down - affects conservation efforts
Damage to local wildlife
Less attractive to tourists
Development of infrastructure may harm environment
Can damage property
Tourism in Glacial Landscapes
Impacts
Strategies to cope with impact of tourists
Economic
Social
Environmental
Positive economic impact
Employment to local people - hotels ect.
Extremely high house prices due to demand for holiday and second homes - locals cant buy and have to move out of area
Increased traffic causes problems
Holiday homes not occupied all year round - some services limited
Footpath erosion - vegetation destroyed and exposed soil washed away
Litter increases during tourist season
Tourists may park on grass verges, causing damage to vegetation
Wildlife disturbed by walkers and dogs
Footpath erosion
Traffic congestion
Protecting wildlife and farmland
Resurface paths with hard-wearing materials
Reseed vegetaion
Encourage visitors to use alternative routes
Increase public transport in tourist season
Improve road network
Encourage other transport
Signs to remind people to take litter home
Bins
Lake District
Impacts
Management Strategies
Gets 16.4 million visitors every year
Environmental
Economic
Social
Catbells is a popular mountain for walkers - but severs erosion has followed
Tourists often park on grass verges in the popular Langdale valley
Noise and pollution of water is caused by boats and water sports on Lake Windermere
Employed over 16000 people in 2014 and visitors spent over £1 billion
Average price of a house in village of Grasmere is over £350000 but average local household income is only £27000, so many locals may not be able to afford to live in area
89% of visitors arrive by car - traffic is heavy
Businesses in village of Ambleside mostly cater for tourists - prices for everyday goods are high and locals often travel to buy most of the food and clothes
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