factors effecting glaciated landscape Flashcards
1
Q
climate
A
Precipitation
- amount if rain or snow
- aeolian processes contribute to glaciated landscapes
Temperature
- how hot/ cold it is = affecting the movement
- temps above 0 = ablation > accumulation -> outputs
2
Q
geology
A
lithology
- physical and chemical composition of rocks
- harder rock = slower erosion
structure
- Properties of individual rock types: jointing, bedding and faulting
- permeability of rocks
3
Q
geology lithology - clay
A
- Clay = weak lithology -> bonds between particles, weak
- Little resistance to erosion weathering mass movements
4
Q
geology lithology - basalt
A
- Basalt (dense interlocking crystals)
- highly resistant
- forms prominent glacial landforms
EX - arêtes and pyramidal peaks
5
Q
geology lithology - limestone
A
- limestone (predominantly calcium carbonate)
- soluble in weak acids -> vulnerable to decay via chemical weathering process of carbonation @ low levels
6
Q
geology - structure - chalk
A
- chalk = pours rocks
- tiny air pores separate the mineral particles
7
Q
geology - structure - carboniferous limestone
A
- primary permeability (these pores absorb & store water)
- secondary permeability ( permeable but water seeps into it bc of its many joints
8
Q
geology - structure - angle of dip
A
- affects the valley side profile
- stronger = parallel structure and equal spaces apart
- weaker = curved and unequal
- can be chipped = exposed areas to water = weakened rocks
9
Q
latitude
A
- How far North from the equator
- High latitude = away from equator, low precipitation levels and low altitudes
EX - Vostok station in Antarctica, 4.5mm of precipitation
High latitudes (low altitudes) = beyond Artic -> Antarctic circles @ 66.5 degreed N&S - dry climates
- little precipitation
- large, stable ice sheets
EX - Greenland & Antarcti
10
Q
altitude
A
- How far above sea levels
- Higher = colder
- High altitude = high precipitation levels
EX - Jasper National park in Canada Rockies = above 600mm - High altitudes (low latitudes)
EX - rocky mountains, Himalayas - variable temperatures
- more summer melting
11
Q
relief
A
- The gradient
- Larger gradient = more energy = more erosion
- Steeper relief = greater resultant force of gravity (GPE)
- Impact on microclimates and the moment of glacier
12
Q
aspect
A
- Placement of the sun
- Aspect of slope faces away from general direction go sun
- Less solar energy received = less melting
- North facing slopes are larger because there’s less sunlight
- Mass balance in these areas positive -> glacier advancing = larger glacier, - —- more erosive power
- Mass balance negative = retreating glacier -> smaller glacier etc
13
Q
ice formation
A
Diagenesis
Formation of glacier
More inputs of precipitation = more pressure = larger glacier = more erosion
14
Q
glacier movement - valley glacier
A
- large, slow-moving masses of ice
- confined by valley sides
- may be outlet glaciers from ice sheets or corrie glaciers
- 10-30km in length
- BUT - Karakoram Mountains, Pakistan = 60km
15
Q
glacial movement - ice sheet
A
- largest accumulation of ice - 50,000km2
- 96% of worlds ice
- Antarctic: covered 13.6 million km2, volume 30 million km2 and thickness 4700m+ deep
