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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