Glaciers Flashcards
(27 cards)
What is freeze thaw weathering?
- water in cracks freeze
- expands
- pressure
- thaws
- repeats
What is plucking?
- bedrock attaches to the base/sides of a glacier
- pulled out as it moves
What is abrasion?
- rocks rub against the bedrock
What is rotational slip?
- lubricated by meltwater
- glacier slides along a curve
What is buldozing?
- material is transported
- carried within, under, above
Why does a glacier deposit material?
during melting or retreat
What are features of glacial erosion?
- pyramidal peaks (3 corries meet)
- Arêtes
- hanging valleys
- truncated spurs
- glacial troughs
- ribbon lakes
What are features of glacial deposits?
- moraine
- drumlins
- erratics
How are glacial troughs formed?
- environment is glaciated
- plucking in valley
- floor is widened due to abrasion
- valley formed with steep sides & a wide bottom (contains a ribbon lake)
How are ribbon lakes formed?
- glacier creates a glacial trough
- some areas are eroded more as the ice is thicker or less resistant rock
- melts = lake
How are corries formed?
- snow accumulation in a hollow
- deeper compresses = corrie glacier
- freeze thaw weathering enlarges the hollow
- plucking steepens back wall
- rotational slip deepens hollow
- raise lip formed (thinner ice reduced erosion)
How are arêtes formed?
- two corries erode back to back
- land becomes narrower
How are pyramidal peaks formed?
- 3 or corries form on mountain sides
erode backwards
leave a singular peak
How are truncated spurs formed?
- glacier in former v shaped valley erodes sides (plucking and abrasion)
- reaches interlocking spurs buldozing through
How do hanging valleys form?
- small glaciers occupy tributary valleys above big glacial trough
- lower rate of erosion valley isn’t eroded at same level
- left hanging above (waterfalls)
How is moraine formed?
- transported eroded material is deposited
- lateral = valley sides
- medial = two lateral
- terminal = across u shaped valley max advance
- ground = carried under foot and melted
How are drumlins (hills of glacial deposits) formed?
- deposited when glacier is overloaded with sediment
- long axis indicates direction of glacier
What are erratics?
- deposited boulders of bedrock
- range in size
The lake district
- North west england
- largest national park uk
- honeypot sites
What are economic uses of the Lake District?
- Quarring
- Forestry
- Farming
-Tourism
What are the benefits and disadvantages of quarrying?
- jobs
- boost economies
- damage natural environments
- unattractive
- lorrie’s = air pollution
What are the benefits and disadvantages of forestry?
- jobs
- boost economy
- conifer trees not native
- reduction in biodiversity
- zip wires spoil peace
What are the positives and disadvantages of farming?
- jobs
-boost economy - disturbs habitats
- footpaths from tourists (animals escape) and litter
How does tourism cause conflict in the lake district?
- 90% arrive by car = congestion and pollution
- increased house prices
- jobs are seasonal and low paid
- water sports damage lakesides
