Glaciers and how they are viewed as a system Flashcards
what is a system?
A system is a set interrelated objects comprising of stores + transfers that are connected to form a working unit.
what type of system is a glacier and why?
Glacier is open system has external Inputs eg energy, precipitation, material and Outputs eg glacial, wind erosion of rock surfaces, meltwater + evaporation.
what stores/throughputs do glaciers have?
Materials that are carried by a glacier are stores eg ice, water + debris accumulation
what is transfer?
the transfer is the movement of a glacier due to gravity, gradient and increasing accumulation at the glacier store
what energies are available to the system?
Kinetic energy is the input from wind + moving glaciers
Thermal energy is absorbed from the sun
Potential energy from position of material on slope from deposition, weathering + mass movement.
what is equilibrium?
when inputs and outputs are equal
when equilibrium is disturbed what happens?
self regulation takes place, this is where it changes form until its back in equilibrium (dynamic equilibrium -> example of negative feedback)
what is the glacier mass balance?
the difference between the amount of snow and ice (accumulation) and the amount of melting (ablation) occurring in a glacier over one year period.
when does the glacier advance?
in the accumulation zone at the upper part, where accumulation > ablation
when does the glacier retreat?
in the ablation zone where ablation > accumulation
what happens to the mass balance seasonly?
advancing in the winter, and retreating in the summer.
what are the outputs?
main output is the loss of water vapour from evaporation of glaciers surface.
calving - blocks of ice break off at glaciers snout
meltwater streams
