First 288 words of the document:
A2 Geography 4.2 Glacial Systems Student Lesson Notes
1. Glaciers as Dynamic Systems.
The Glacier System of Inputs, Outputs and Stores.
Glacier: An extensive body of land ice, consisting of ice crystals, trapped air, water and rock debris, which exhibits evidence of down slope movement under the
influence of gravity. These include:
· Cirque Glacier: a small glacier occupying a glacially eroded "arm-chair" shaped hollow in a mountainous region.
· Valley Glacier: a glacier that occupies a pre-glacial valley, either resulting them the coalescence of several cirque glaciers (Alpine type) or flowing from
the edge of an ice cap or ice-sheet (outlet glacier).
· Icecap: A dome shaped covering of ice, small than an ice-sheet and often in a mountainous area, such as on Iceland or Baffin Island.
· Ice-Sheet: A large, continuous layer of land ice of considerable thickness, such as in Antarctica or Greenland. It is larger than an ice cap.
Firn: German term for old granular snow which is in the process of being transformed into glacial ice. It has a density between 0.4 and 0.9kg m-3
Glacial ice: Ice, which forms from the recrystalisation of firn (firnification)
Inputs: a combination of the accumulation of the mass and energy of glacial ice plus the rock debris that it transports.
Outputs: a combination of loss of ice and energy through ablation plus the removal or deposition of rock debris, either directly as a glacial deposit or indirectly as
part of the meltwater's load.
Glacial system stores: the rock, ice water and air of which a glacier is composed.
Meltwater: water resulting from the melting of glacial ice or snow.
Other pages in this set
Here's a taster:
Annual Glacier Budget (Accumulation and Ablation).
Accumulation: the process of snow and ice nourishment of a glacier form precipitation (snow and freezing rain), rime ice, from direct sublimation, hoarfrost,
avalanche material and drifting snow.
Ablation: the wastage or removal of surface snow or ice by melting, evaporation and sublimation. The process involves the transfer of heat from the glaciers
surroundings (sensible heat, latent heat and conducted heat) and direct insolation (radiation from the sun).…read more
Here's a taster:
The Impact of the Annual Budget on Advance and Retreat.
Glacial advance: the state of a glacier when its front or snout is advancing. This state is reached when accumulation exceeds ablation leading to a positive mass
Glacial retreat: the state of a glacier when its front or snout is receding, although the body of the ice itself is still moving forward. This state is reached when
ablation exceeds accumulation leading to a negative mass balance.…read more