What am I?

You can find me at high altitudes and high latitudes I need high snowfall in winter and cool temperatures

in summer I move slowly downhill I have sculpted mountains and carved out valleys I use the processes of erosion, transportation and

deposition to change the landscape I am a big river of ice

Perito Moreno Glacier, Argentina.

An introduction to glacial processes and landscapes

What is glaciation? How are glaciers formed?

How do glaciers shape the landscape? Upland features

Lowland features

Hubbard Glacier, Alaska.

Glaciation is the study of ice and its impact on the environment.

The Ice Age in Britain began approximately one million years ago and ended about 20,000 years ago.

Northern and Eastern parts of the British Isles were covered in ice.

Glaciers were formed which moved down valleys, carving out new features.

What is glaciation?

How are glaciers formed?

Glaciers are long standing masses of ice. They form in hollows (corries) on the colder,

sheltered side of a mountain Snow and ice gathers in the hollow and over time the

corrie gets larger. Inside the hollow the ice begins to move in a circular

motion. Eventually the ice will move out of the corries and

over the lip of the hollow. The glacier begins to move slowly down the

mountain.

How do glaciers shape the landscape?

Main processes:

Abrasion- the fragments of rock transported by the glacier grind along the valley bottom and sides, wearing away the rock.

How do glaciers shape the landscape?

MAIN PROCESSES:

Plucking- meltware at the base of the glacier freezes on the rock surface. As the glacier moves forward it extracts the pieces from the rock surface.

Freeze thaw – is a type of weathering where water settles in cracks in the rock surface, freezes and expands, pressurising surrounding rocks. It then thaws and contracts, releasing the pressure. This process loosens the surface layer of rock.

Upland features

Corrie - an arm chair shaped hollow found in the side of a mountain.

Upland features

Arête – a narrow knife edge ridge separating two corries.

Carn MÔr Dearg Arête- Ben Nevis

Upland features

Pyramidal peaks – when three or more corries form in the side of one mountain

The Matterhorn

Upland features

Tarn – a lake found in a corrie.

Red Tarn, Helvellyn.

Glaciers

Franz Josef Glacier, New Zealand.

Lake Fryxell formed from the Canada Glacier, Antarctica.

Vatnajokull Glacier, Iceland.

Lowland features

http://www.bbc.co.uk/schools/gcsebitesize/audio/geography/

Your task: listen to the sound clip and note down new terminology.

New terminology

Lowland featuresU

shaped valley

Hanging valleys waterfallsTruncated spurs

Misfit streams

Ribbon lakesRock steps

This can be done on a white board…….ask the class to feed their answers back.

Summary

Today we covered the physical elements of glaciers - what the are

- how they are formed- the main processes- upland features-lowland features

Homework- find examples of the lowland features we listed on the board. Please state the name of the feature, its location and include a picture. Due : 20/09/09

Next lesson we will look at the human implications with a focus on the Lake District.