Geo - Glaciation Flashcards
How do glaciers form
Snow which never melts, layers up compressing to form ice and starts to slip downhill where it’ll eventually melt
What’s the snowline
The line where ice doesn’t ever melt
What is the birthplace of glaciers
Corries
What is basal slippage
Where meltwater Underneath the glacier lubricates it allowing it to slip downhill
What’s a cravace
A crack in glacial ice
What’s a glacial surge
Where large amounts of ice move hundreds of meters
What’s moraine
Material being carried by the glacier which has fallen from the valley sides
What is abrasion in a glacier
The sandpapering effect where rocks being carried by the glacier grind away at the valley sides eroding them away
What is plucking
Where rocks are ‘plucked’ as meltwater freezes and bonds them to the moving glacier
Where is moraine deposited
At the snout of the glacier where the ice melts
What is glacial till/Boulder clay
The rocks left behind as the glacier retreats
What is a drumlin
Large hills of glacial till caused by rapid retreat
How can glacial till be sorted
Through meltwater rivers which carry the sediment
What is internal deformation
Where ice crystals slowly deform aligning and allowing the glacier to move - very slowly - only in very cold conditions where there is no meltwater
Define a Corrie
Large hollowed out depressions found on the upper slopes of glaciated valleys
How does a Corrie form
- Snow gathers in slight depressions in the rock compressing into ice over many years
- Glacial ice builds up and deepens the depression though plucking and abrasion as the glacier moves through rotational slip
- After the glacial period the Corrie fills with meltwater becoming a tarn (Corrie lake) with a rock lip due to the deposition of moraine
What is an arête
Where two corries meet forming a knife-edge ridge
What is a pyramidal peak
Where three or more corries form a single peak
How is a U-shaped valley formed
As a glacier moves through a V-shaped valley it erodes away deepening and widening it forming a flat bottomed valley
What are truncated Spurs
Where interlocking Spurs are destroyed as a glacier cannot move around them forming a singular straight valley
What are ribbon lakes
Deep and long lakes at the base of a U-shaped valley
How are ribbon lakes formed
A higher rate of erosion in a glacier either from
1. the glacier meeting a softer rock (geology) or
2. The meeting of a tributary glacier which would increase the ice mass and therefore increase the rate of erosion
After the glacial period these hollows fill with meltwater becoming ribbon lakes
What is a hanging valley
Where a tributary glacier cannot erode to the same level as the main glacier, often marked with a waterfall
What is lateral moraine
Rocks which have fallen from the valley sides onto the glacier, building up on the sides
What is medial moraine?
When two glaciers meet their lateral moraine in the centre joins up making a string of moraine at the centre of the surface of the glacier
What is terminal moraine
Moraine built up at the snout of a glacier often reaching tens of meters high
What is ground moraine?
Rocks trapped within the ice, essential for abrasive erosional processes
What are four economic ways of using glaciated areas in the UK
- Farming of sheep
- Planting of conifer trees
- Quarrying
- Tourism
How is farming carried out in glaciated areas?
In upland areas sheep are used as the uneven rocky ground has not much use
In valleys soil is thicker and land is flat so perfect for farming equipment
In lowland areas fertile till deposits make it easy to farm on the rolling hills
Why are conifer trees planted in glaciated areas?
They are well adapted to acidic soils and only take 20-30 years to grow where they can be harvested for paper or the construction industry
How is quarrying an economy opportunity in glaciated areas?
Hard rock, sand and gravel can be used the the construction industry
Limestone found in the Pennines can be used in the chemical industry
What are the benefits of tourism in glaciated areas
They provide huge economic opportunities
They provide employment for thousands
What are the disadvantages to tourism in glaciated areas
Environmental damage
Lack of job security
Exploitation of culture
Why are wind turbines suited to glaciated landscapes?
Glaciated landscapes are exposed with only a very small population
What problems may wind turbines cause in glaciated areas
Some people think they’re ugly and may drive away tourists from the area damaging the local economy
What conflicts can occur from quarrying in glaciated areas
Can lead to pollution of land and can spoil the landscape
What conflicts can occur from tourism in glaciated areas?
Can cause conflicts with local land owners on how best to use the land
What conflicts can occur from water storage in glaciated areas?
Dams can cause environmental conflicts as land won’t be able to flood
What are erratics and how do they form?
They are glacial deposited rocks which were carried by the glacier and then left behind as it retreated
What is the significance of an erratic
They can be used to trace the path of an ancient glacier
What are drumlins and how do they form
Drumlins are specifically shaped hills that form when a glacier deposits large amounts of material, then pushes it and makes it streamlined
