Key Definitions Flashcards
Ablation
The loss of mass from a glacier eg. Meltwater, avalanches, sublimation, evaporation
Abrasion
Small rocks within the base of the glacier rub against the bedrock
Accumulation
The addition of mass to the glacier, usually as snow
Active layer
The top layer of soil above permafrost, which thaws annually in summer
Alpine regions
Areas of low temperature in high altitude, mountainous regions
Basal ice melting
The weight of a temperate glacier causes meltwater, which will then erode the bedrock through fluvial erosion
Basal sliding
Glaciers sliding over bedrock, due to meltwater between the 2 surfaces
Cold based glacier
The glaciers temperature remains below 0C so the base of the glacier remains frozen and moves very little
Compressional flow
Ice builds up and thickens due to friction as a glacier travels upwards along a shallow gradient
Crushing
The weight of the glacier causes fracturing in the bedrock
Environmental fragility
An environment is vulnerable or at risk, with low resilience or ability to adapt to changes
Extensional flow
Ice thins out, creating crevasses, due to an increase in the glaciers velocity down a shallow gradient
Fluvial erosion
Water within the glacier erodes the base of the glacier over time
Frost heave
The freezing and expansion of water beneath the ground, resulting in floor uplift
Glacial budget
The difference between accumulation and ablation for a glacier
Glacial period
A period of time of colder average global temperatures causing the growth of ice cover, glacial advances and sea levels to fall
Holocene epoch
Our current glacial period of limited ice cover, lasting over 10,000 years
Interglacial period
A period of time of warmer average global temperatures, resulting in reduced ice cover, glacial retreat and sea levels to rise
Internal deformation
Glacial movement caused by the weight of the glacier above deforming the ice
Milankovitch cycles
Changes to the tilt and shape of the orbit will affect the average temperature of the Earth
Nivation
Erosional process involving snow and ice
Orbital eccentricity
How far a planets orbit is from being a perfect circle
Periglacial
Landscapes found at the edge of a glacier, polar and alpine regions. Permafrost occurs, with low precipitation and only highly adapted plant species survive
Permafrost
Permanently frozen soils throughout the year
Plucking
Rocks on the bedrock are frozen within the glacier. As the glacier moves, the rocks are pulled from the bedrock and moved
Polar regions
Areas of maximum ice sheets and limited vegetation, located at high altitudes on earth
Solifluction
The movement of waterlogged soil, trapped between the active layer and permafrost
Warm based glacier
Faster travelling glaciers due to basal meltwater trapped underneath the glacier, acting as lubrication to allow the glacier to move
Striation
Scratches or grooves that are found on the surface of rocks, created by the movement of glacial ice
