Glacial Landscapes in the UK Flashcards
All 39 cards in this deck
How far south did ice reach across the UK at its maximum extent in the last ice age?
Ice covered all of Scotland, Wales, Ireland and northern England, reaching a line roughly from the Bristol Channel across to the Thames Estuary/Norfolk. Southern England stayed ice-free.
True or false? During the last ice age the ice sheet was deeper over the British Isles than over Scandinavia.
False. It was much deeper over Scandinavia (over 2500 m) than over the British Isles (just over 1500 m).
What are the steps of freeze-thaw weathering?
e.g. on a bare rock face above a glacier- Water collects in a crack in the rock — e.g. meltwater fills cracks in the rock face.
- Temperature falls below 0°C; the water freezes and expands by about 9%, widening the crack.
- Repeated freezing and thawing shatters the rock — angular scree falls onto the glacier.
What is abrasion by a glacier?
Rock debris frozen into the base and sides of the glacier is dragged over the bedrock, scraping and smoothing it like sandpaper (leaving striations).
What is plucking by a glacier?
Meltwater at the base of the glacier freezes onto the rock; as the ice moves it tears lumps of rock away, leaving a jagged surface.
What is rotational slip?
The circular, curved movement of ice within a hollow, which deepens the hollow into a corrie.
What is bulldozing by a glacier?
The snout of an advancing glacier pushes loose material in front of it forwards.
Why do glaciers deposit sediment?
When the ice melts the glacier loses energy and can no longer carry its load, so material is dropped — mostly at and beyond the snout.
True or false? Glacial till is unsorted but outwash is sorted.
True. Till is dropped straight from the ice as a mixed, angular, unsorted deposit; outwash is carried by meltwater, so it is sorted with finer material further from the snout.
What are the steps in the formation of a corrie?
e.g. Cwm Idwal, Snowdonia- Snow collects in a hollow on a mountainside and compacts into ice.
- Rotational slip and abrasion deepen the hollow; plucking and freeze-thaw steepen the back wall.
- Thinner ice at the front leaves a rock lip, so a tarn fills the hollow after melting — e.g. Llyn Idwal.
True or false? In the UK, corries are most often found on south-facing slopes.
False. They are usually north- or north-east-facing, because these shaded slopes kept snow and ice longest.
What is an arête and how does it form?
A narrow, steep-sided knife-edge ridge, formed where two corries erode back to back.
What is a pyramidal peak and how does it form?
A sharp, pointed mountain summit, formed where three or more corries erode back to back around a mountain.
What is a glacial trough and how does it form?
A straight, steep-sided, flat-floored U-shaped valley, formed where a glacier widened and deepened a former V-shaped river valley by abrasion and plucking.
What is a truncated spur and how does it form?
A steep, blunt-ended cliff on a valley side, formed where the glacier cut off (truncated) the ends of interlocking spurs that stuck into the valley.
Give two characteristics of a ribbon lake.
It is long and relatively narrow, and it occupies the floor of a glacial trough.
How does a ribbon lake form?
The glacier eroded a deeper hollow where the rock was softer (or a moraine dammed the valley), and the hollow later filled with water.
What is a hanging valley and how does it form?
A smaller tributary valley left high above the main glacial trough, because the tributary glacier was smaller and eroded less deeply; a waterfall often drops from it.
What is an erratic?
A large boulder transported by ice and deposited in an area of a different rock type.
Describe the shape of a drumlin.
An elongated, egg-shaped or oval low rounded hill of till, with one side steeper than the other.
On a drumlin, which end shows the direction the ice came from?
The steeper, blunter end faces the direction the ice came from; the gently tapering end points the way the ice was moving.
What is lateral moraine?
A ridge of material along the sides of a glacier, built up from freeze-thaw debris falling from the valley sides onto the ice edges.
What is medial moraine?
A line of material running down the middle of a glacier, formed when two glaciers merge and their lateral moraines join.
What is terminal moraine?
A ridge of till deposited across the valley at the furthest point the glacier snout reached.
Give two pieces of evidence on an OS map or photograph that an upland area was glaciated.
A long narrow ribbon lake, and a steep-sided glacial trough with a flat valley floor. (Also moraine/till deposits or corries with tarns.)
Name one landform of erosion and one of deposition found in Snowdonia.
Erosion: the corrie Cwm Idwal (or the ribbon lake Llyn Ogwen). Deposition: moraine ridges on the floor of the Ogwen valley.
Why are glaciated upland areas attractive for tourism?
Dramatic glacial scenery — mountains, corries and ribbon lakes — allows walking, climbing, water sports and sightseeing.
Why is forestry common in glaciated upland areas?
Coniferous plantations grow on steep, wet, poor-quality land of little use for crops, and the timber is sold for construction and paper.
Why does quarrying take place in glaciated upland areas?
Glacial erosion has exposed valuable hard rock at the surface, e.g. slate quarried at Honister in the Lake District.
Give one conflict between tourism and farming in a glaciated upland area.
Walkers leave gates open, damage walls and trample land, and dogs disturb sheep, costing farmers money.
Give one conflict between development and conservation in a glaciated upland area.
A new quarry, road or housing brings jobs and income but scars the protected landscape and destroys habitats in a National Park.
True or false? A National Park in a glaciated upland aims to prevent all development.
False. It aims to conserve the landscape while also meeting the needs of residents and the local economy.
Give two attractions for tourists in the Lake District.
Ribbon lakes such as Windermere for water sports and cruises, and mountains such as Scafell Pike for walking and climbing.
Give two environmental impacts of tourism in the Lake District.
Footpath erosion on the fells, and traffic congestion causing air pollution (plus litter and shoreline damage from boats).
Give one social and one economic impact of tourism in the Lake District.
Social: second homes and holiday lets push house prices beyond local people. Economic: tourism creates jobs and income for local businesses.
Give two strategies used to manage the impacts of tourism in the Lake District.
'Fix the Fells' footpath repair and restoration, and traffic management such as park-and-ride and improved public transport.
Why was the 10 mph speed limit on Windermere controversial?
It reduced noise, bank erosion and accidents, but water-sports businesses and hotels lost visitors, income and jobs.
True or false? Freeze-thaw weathering needs temperatures that repeatedly rise above and fall below 0°C.
True. Water must melt to seep into cracks and then refreeze and expand, so repeated crossing of freezing point is needed.
True or false? Most jobs created by tourism in the Lake District are full-time and well paid.
False. Many tourism jobs are seasonal, part-time and low paid.