How can glaciated landscapes be viewed as systems 2.1 Flashcards
(18 cards)
whats glacier mass balance
the difference between the amount of snow and ice accumulation and the amount of ablation occurring in a glacier over a one year period
cold based glaciers
- low altitude
- low relief
- basal temperatures below the pressure point
- very slow rates of movement, perhaps a few meters/cm a year
warm based glaciers
- high altitude locations
- steep reliefs
- basal temperatures alter above the pressie melting point
- rapid rates of movement, typically 20-200 m/year
what are the open systems
means energy and matter can be transferred from neighbouring systems as an input. it can also be transferred to neighbouring systems as an output
whats a input
energy eg kinetic energy from wind
material from deposition weathering and mass movement from slopes
whats an output
glacial and wind erosion
evaporation
whats equilibrium
when a systems outputs and inputs are equal
whats dynamic equilibrium
when the equilibrium is disturbed, the system produces its own response to the disturbance. this response is an example of negative feedback
whats ablation
refers to all processes that remove mass from a glacier
what are the two key aspects that influence glaciated landscape systems
lithology and structure
whats lithology
describes the physical and chemical composition of rocks. for example some rocks such as clay have a weak lithology, with little resistance to erosion.
whats structure
concerns the properties of individual rock types such as jointing, bedding and faulting. it also includes the permeability of rocks.
high altitude
- beyond the artic and antarctic circles
- 66.5 degrees north and south
- tend to have cold dry climates with little seasonal variation in precipitation
low altitude
- high precipitation inputs
- variable temperatures
- more summer melting
what is relief
the term used for the differences in height from place to place on the land’s surface
effects of relief
the steeper the relief of the landscape the greater the resultant force of gravity and the more energy a glacier will have to move downslope.
whats aspect
the direction that a slope faces
effect of aspect
if the aspect of the slope faces away form the general direction of the sun, temperatures are likely to remain below zero for longer as less solar energy is received and so less melting occurs.
