AQA Geography - Glacial systems and landscapes keywords

Ablation - The loss of mass from the glacier, e.g. 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.

Arêtes - A ridge formed between two corries.

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 two surfaces.

Blockfields - Rock-strewn landscape caused by extensive frost action.

Cold-Based Glacier - (Also called Polar Glaciers) The glacier’s temperature remains below zero

degrees, 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.

Corries - A round hollow in the side of a hill, widened from an initial smaller hollow by a glacier

within the hollow.

Crushing - The weight of the glacier causes fracturing in the bedrock.

Drumlins - When a glacier hits an obstacle that cannot be eroded, deposition from underneath the

glacier builds up behind the obstacle.

Environmental Fragility - An environment is vulnerable or at risk, with low resilience or ability to

adapt to changes.

Erratics - Boulders transported and deposited by a glacier. The type of rock that forms the erratic

will usually differ from the rock types in the surrounding landscape.

Esker - A long, winding ridge of glacial deposition.

Extensional Flow - Ice thins out, creating crevasses, due to an increase in the glacier’s velocity

down a shallow gradient.

Fluvial Erosion - Water within the glacier erodes the base of the glacier over time through:

hydraulic action, attrition, corrosion.

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Frost Heave - The freezing and expansion of water beneath the ground, resulting in floor uplift.

Glacial Budget - The…