Glacial landscapes in the UK Flashcards
Why do glaciers move downhill
Because of gravity and the weight of the ice
Basal Sliding
The movement of glaciers using meltwater under the ice as lubricant
Abrasion
Rock stuck in the ice grinds against rock underneath the glacier
Plucking
Meltwater freezes onto the rock at the sides and base of the glacier. When the glacier moves forward the rock gets pulled out and along with it.
Rotational Slip
Ice moves in a circular rotation eroding landscape into bowl shapes
Freeze thaw weathering
Water in cracks freezes and expands putting pressure on the rock. Then the ice thaws releasing the pressure. Repetition of this weakens the rock.
What does plucking do
It steepens the back wall of the Corrie
What does abrasion do
It deepens the Corrie base
Till
A mixture of material carried by glaciers
Arête
A narrow steep sided ridge formed when two glaciers flow in parallel valleys
Corrie
Steep sided armchair shape with a lip at the bottom end
Ribbon lakes
Long thin lake formed when soft rock gets eroded faster than surrounding hard rock
U-shaped valley
Steep sided valley with a flat floor. Formed when the glacier erodes a v-shaped valley into a U-shaped valley.
Pyramidal peak
Pointed peak formed by at least three back to back glaciers
What is the last 1.8million years called
Pleistocene
How many years ago did the last glacial end
10 000 years ago
What causes the interglacial peroids
to do with the orbit of our planet around the sun and its tilt
Formation of a glacier
Ice forms where enough snow builds up and pressure causes it to slowly compact and increase in density. This process takes more than a hundred years
subglacial material
material is plucked from the rock beneath the glacier so is carried under the ice
Englacial material
some materials fall into crevasses and is carried in the ice
supraglacial material
some material falls onto the ice from surrounding mountain sides and is carried on top
Bulldozing
when a glacier moves forward it acts like a giant earthmover, bulldozing piles of rock debris in front of it.
where does moraine come from
when sediment that was carried along by the glacier gets deposited
What is a positive mass balance
when accumulation is greater than ablation
Inputs at an accumulation zone
Avalanches and snowfall
Outputs at an ablation zone
Evaporation and outwash
What is the Net Glacier Balance
where the gain from accumulation matches losses from ablation
Why do corrie lips form
because there is less erosion at the front where the glacier leaves the corrie hollow to flow down the valley
Example of an Arete
Crib Goch, Snowdonia in North Wales
Example of a Glacial Trough
Nant Francon Valley, Snowdonia, North Wales
2 ways of making ribbon lakes
Differential erosion
When 2 glaciers join (they are more powerful together so erode the basin floor easier)
How are interlocking spurs formed
when a river erodes the upper valley it cuts down while meandering in and out of the surrounding rock
What are drumlins
smooth, long mounds of material formed parallel to the ice movement, often found in swarms
How are drumlins created
When the glacier deposits material too heavy to carry any longer and forms mounds. This then gets smoothed over time and ends up with a smooth uphill side and a steep downhill side
How are drumlins used in the present day
- good for hill sheep farming
- good for settlements as they raise the land. houses can be build above the muddy flood plain
Moraine
Unsorted material produced by glacial erosion
Ground Moraine
Found underneath the glacier
Terminal moraine
Found deposited in a ridge at the maximum advance of the ice
Lateral moraine
come from the valley side and are found running parallel to those valley sides
Medial moraine
Found running down the middle of a valley formed by two lateral moraines from two glaciers coming together
Recessional Moraine
Found running parallel to terminal moraine and mark the retreat of a glacier where the ice has been static for long enough
Five types of moraine
Ground
Terminal
Lateral
Medial
Recessional
Example of a location of drumlins
to the South East of Kendal
How does quarrying in Upland areas attract tourists
Some slate mines and quarries are becoming tourist attractions as they are sometimes used in films
Quarrying in upland areas
Granite, slate and limestone quarried extensively
Lake District is the centre of slate quarrying which is used for roofing tiles
What farming is done in upland areas
NO CROPS
steep slopes, high rainfall, cool temperatures, low sunshine, hard rocks and thin soils mean that they aren’t possible
HILL SHEEP FARMING
it occupies large areas of land and is low in intensity of capital and labour
How are the upland areas used for forestry
extensive coniferous woodland been planted as it is very fast growing
used for timbre, furniture, biofuels and building
How are the upland areas used in tourism
Lakes and mountains offer walking, climbing and watersports
military training means low flying planes = free air show
beautiful scenery
