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Flashcards in Ice On The Land Deck (31):
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El Nino effect

A periods blip in the usual global climate characteristics caused by a short term reduction in the intensity of the cold ocean currents that normally exist in the west coast of South America. It results in unusual patterns of temperature/rainfall and can lead to droughts/flash floods etc. in some parts of the world

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Interglacial

A period of ice retreat associated with rising temperatures

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Glacial period

A period of ice advance associated with falling temperatures

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Ice sheet

A large body of ice over 50000km2 in extent. Unconfined by topography

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Ice cap

A smaller body of ice (less than 50000km2) usually found in mountainous regions

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Glacier

A finger of ice usually extending downhill from a nice cap and occupying a valley. Confined by topography

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Accumulation

Inputs into the glacier budget, such as snow melt and avalanches

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Topography

The shape of the land

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Ablation

Outputs from the glacier budget, such as melting

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Snout

The front/end of a glacier

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Glacier budget

The balance between the inputs (accumulation) and outputs (ablation) of a glacier

11

Abrasion

Rock fragments carried by ice function as "sandpaper" that scouts surface over which the ice moves. This process produces striations (long grooves and scratches cut into bedrock), and glacial polish (a very smooth surface produced by fine abrasion of bedrock by rock flour)

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Plucking

Meltwater penetrates into bedrock cracks and refreezes, prying angular blocks of rock loose. These blocks may be incorporated into the ice, producing glacial erratics which can be transported long distances.

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Glacial erratics

Boulders sometimes formed during plucking

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Rotational slip

Slippage of ice along a curved surface

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Moraine

Sediment carried and deposited by the glacier

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Bulldozing

The pushing of sediment at the snout of the glacier as it advances

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Corrie

A deep depression on a hillside with a steep back wall often containing a lake

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Scree

Loose rock on the back walls of corries

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Arête

A knife edged ridge, often formed between two corries

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Pyramidal peak

A sharp edged mountain often formed by three back to back corries

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Glacial trough/U-shaped valley

A wide steep sided valley eroded by a glacier

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Truncated spur

An eroded interlocking spur characterised by having a very steep cliff

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Hanging valley

A tributary glacial trough perched up on the side of a main valley, often marked by a waterfall

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Ribbon lake

A long narrow lake in the bottom of a glacial trough

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Long profile

This shows the changes in height and shape along the length of the glacier, from it's source high in the mountains to it's snout

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Sustainable management

A form of management that ensures social, economic and environmental needs are balanced and developments are long lasting

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Fragile environment

An environment that is easily impacted and damaged by human activity

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Avalanche

A rapid downhill movement if a mass of snow, ice and rocks, usually in a mountainous environment

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Loose snow avalanche

A powdery avalanche usually from a single start point

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Slab avalanche

A large scale avalanche formed when a slab of ice and snow breaks away from the main ice pack