What you'll learn
Thousands of years ago, much of the UK was covered by ice, and the glaciers that flowed across the land carved out dramatic landscapes that we still see today. For AQA GCSE Geography you need to understand how glaciers shape the land through erosion, transport and deposition, and be able to identify and explain the landforms they create. This guide covers glacial processes, erosional landforms, depositional landforms, and land use in glaciated areas. By the end you should be able to explain how glacial landforms are created and interpret them on a map.
Key terms and definitions
Glacier — A large mass of ice that moves slowly downhill.
Erosion — The wearing away and removal of rock by the glacier.
Abrasion — Erosion caused by rock frozen in the ice scraping the ground like sandpaper.
Plucking — Erosion where ice freezes onto rock and pulls pieces away as it moves.
Freeze-thaw weathering — The breaking of rock as water freezes and expands in cracks.
Moraine — Rock debris transported and deposited by a glacier.
Corrie — An armchair-shaped hollow high on a mountain where a glacier began.
Deposition — The dropping of material carried by the glacier when the ice melts.
Core concepts
Glacial processes
Glaciers shape the land through weathering, erosion, transport and deposition:
- Freeze-thaw weathering breaks up rock: water gets into cracks, freezes and expands, and repeated freezing and thawing shatters the rock.
- Erosion by glaciers happens in two main ways. Abrasion is where rock fragments frozen into the ice scrape the ground beneath, wearing it away like sandpaper. Plucking is where meltwater freezes onto the rock, and as the glacier moves it pulls (plucks) pieces of rock away.
- Transport — glaciers carry huge amounts of rock debris, both on top of and within the ice.
- Deposition — when the ice melts, the material it carried is dropped, forming depositional landforms.
Erosional landforms
Glacial erosion creates several distinctive landforms:
- Corrie (cirque) — an armchair-shaped hollow high on a mountainside where the glacier began, deepened by abrasion and plucking. It often contains a small lake (a tarn) after the ice melts.
- Arête — a narrow, knife-edged ridge formed between two corries eroding back to back.
- Pyramidal peak — a sharp, pointed mountain peak formed where three or more corries erode back towards each other.
- Glacial trough (U-shaped valley) — a wide, deep valley with steep sides and a flat floor, formed as a glacier erodes a former V-shaped river valley into a U shape.
- Ribbon lake — a long, narrow lake on the floor of a glacial trough, where the glacier eroded a deeper section.
- Hanging valley — a smaller valley left high up on the side of a glacial trough, where a smaller glacier joined the main one; a waterfall often flows from it.
Depositional landforms
When a glacier melts, it deposits the material it was carrying, called moraine (unsorted rock debris):
- Terminal moraine — a ridge of material deposited at the furthest point the glacier reached (its snout).
- Lateral moraine — material deposited along the sides of the glacier.
- Medial moraine — a ridge of material in the middle, formed where two glaciers meet and their lateral moraines join.
- Ground moraine — material spread across the valley floor beneath the glacier.
Glaciers can also carry and deposit large boulders far from their origin, called erratics, which are rocks of a different type from the local bedrock.
Identifying landforms on a map
A common exam skill is recognising glacial landforms on an Ordnance Survey map. Clues include contour lines showing steep-sided, flat-bottomed U-shaped valleys, small round tarns high in corries, long thin ribbon lakes on valley floors, and knife-edged arêtes shown by contours very close together along a ridge. Being able to read these features from contour patterns is often tested.
Land use and management in glaciated areas
Glaciated upland areas are used in different ways, which can create conflict. Uses include farming (often sheep farming on the poor upland soils), tourism (walking, climbing and sightseeing in dramatic scenery), forestry, and quarrying. These uses can conflict — for example, tourism can cause footpath erosion, traffic and litter, which affects farmers and local communities. Managing glaciated areas involves balancing these different demands while protecting the landscape.
How glaciers transport material
As well as eroding and depositing, glaciers transport enormous amounts of rock and debris, and understanding this links the erosional and depositional landforms. A glacier carries material in several ways: on its surface (from rockfalls off the valley sides), within the ice (frozen into it), and beneath it (dragged along the base). This is why glaciers can move huge boulders long distances, later dropping them as erratics. The material carried at the sides forms lateral moraine, and where two glaciers merge, their lateral moraines join in the middle to form medial moraine. Seeing transport as the link between erosion (where the material comes from) and deposition (where it ends up) helps explain how the different landforms are connected.
How glacial landforms formed in the UK
It is worth understanding the context of these landforms in the UK. During the last Ice Age, much of northern Britain was covered by ice, and glaciers flowed through upland areas such as the Lake District, Snowdonia and the Scottish Highlands. As the climate warmed and the ice melted (around 10,000 years ago), it left behind the landscape we see today — the corries, arêtes, U-shaped valleys and lakes of these upland regions. This is why the most dramatic glacial scenery in the UK is found in these highland areas, and why they are popular for tourism. Knowing that these landforms are relict features, left by ice that has since melted, helps explain why the UK has such landscapes without any glaciers today.
Worked examples
Example 1: How a corrie forms
Explain how a corrie is formed. Snow collects in a hollow high on a mountain and compresses into ice. The ice erodes the hollow deeper by abrasion (scraping) and plucking (pulling away rock), and freeze-thaw weathering steepens the back wall. This creates an armchair-shaped hollow, which may hold a tarn (lake) after the ice melts.
Example 2: Distinguishing erosion processes
Explain the difference between abrasion and plucking. Abrasion is where rock fragments frozen in the ice scrape and wear away the ground beneath, like sandpaper. Plucking is where meltwater freezes onto rock and the moving glacier pulls pieces of rock away. Both are types of glacial erosion.
Example 3: A U-shaped valley
Explain how a glacial trough (U-shaped valley) forms. A glacier flows down a former V-shaped river valley, eroding it by abrasion and plucking. The powerful erosion widens, deepens and straightens the valley, changing its shape from a V to a wide, steep-sided, flat-bottomed U shape.
Example 4: Identifying moraine
What is a terminal moraine and where is it found? A terminal moraine is a ridge of unsorted rock debris deposited at the furthest point the glacier reached (its snout). It marks the maximum extent of the glacier.
Common mistakes and how to avoid them
A common error is confusing abrasion and plucking. Abrasion scrapes (like sandpaper); plucking pulls rock away by freezing onto it. Learn both clearly, as they are frequently tested.
Students often muddle the types of moraine. Terminal = at the snout (furthest point); lateral = sides; medial = middle (where two glaciers meet); ground = beneath the glacier. Learn the positions.
Another mistake is confusing erosional and depositional landforms. Corries, arêtes, pyramidal peaks and U-shaped valleys are formed by erosion; moraines and erratics are formed by deposition.
When explaining landform formation, give the processes (freeze-thaw, abrasion, plucking) in a clear sequence, not just a description of the shape. Marks are for the process.
Finally, when reading maps, remember a U-shaped valley shows as steep sides with a flat floor, and a tarn is a small round lake high in a corrie. Do not confuse these with river landforms.
Exam technique for "Physical Landscapes in the UK: Glacial Landscapes"
Learn the glacial processes (freeze-thaw weathering, abrasion, plucking) and be ready to use them to explain how each landform forms, in a clear step-by-step sequence.
Be able to identify erosional landforms (corrie, arête, pyramidal peak, U-shaped valley, ribbon lake, hanging valley) and depositional landforms (the four moraines, erratics), and to recognise them on an OS map from contour patterns.
For land-use questions, describe the different uses (farming, tourism, forestry, quarrying) and the conflicts between them. Use precise terms — abrasion, plucking, corrie, moraine — throughout, and support map answers with grid references where asked.
Quick revision summary
- Glaciers shape the land by freeze-thaw weathering, erosion (abrasion = scraping, plucking = pulling rock away), transport and deposition.
- Erosional landforms: corrie (armchair hollow, may hold a tarn), arête (knife-edge ridge), pyramidal peak, U-shaped valley (glacial trough), ribbon lake, hanging valley.
- Depositional landforms: terminal (snout), lateral (sides), medial (middle) and ground moraine, plus erratics (boulders carried far).
- Identify landforms on OS maps from contour patterns (steep-sided flat-floored valleys, round tarns, thin ribbon lakes).
- Glaciated areas are used for farming, tourism, forestry and quarrying, which can conflict and must be managed.