Edexcel A-Level Geography: Glaciated Landscapes and Change Revision Guide

Glaciated Landscapes and Change is one of the optional landscape routes in Edexcel A-Level Geography, examined on Paper 1 as Topic 2A. You sit either this option or Coastal Landscapes and Change (Topic 2B); your centre chooses, and the two are mutually exclusive. The topic rewards candidates who can think in terms of systems -- inputs, stores, transfers and outputs of energy and material -- rather than simply memorising a list of landforms.

This guide covers the full specification content for glaciated landscapes, the processes and landforms examiners expect you to explain, the real-world examples that lift an answer, and how to write high-scoring extended responses. For lesson-by-lesson coverage alongside it, see our Glaciated Landscapes and Change course.

Glaciated Landscapes as Systems

The Edexcel specification frames glaciated landscapes through enquiry questions, and your revision should be structured around them: how have glaciated landscapes developed over time; what processes operate within glacier systems; how do glacial processes contribute to the formation of landforms; and how are glaciated landscapes used and managed today.

A glacier is best understood as an open system. Inputs are mainly snowfall, but also avalanching, wind-blown snow and rockfall debris. These are converted to ice and stored within the glacier. Energy enters as solar radiation, gravitational potential energy and geothermal heat. Transfers occur as the ice moves downslope and as meltwater flows through and beneath it. Outputs include meltwater, evaporation and sublimation, and calved icebergs where a glacier reaches the sea or a lake.

Distinguish the two broad ice masses. Ice sheets are continental in scale -- only Antarctica and Greenland remain today, though Pleistocene sheets covered much of North America and Europe. Valley (alpine) glaciers are confined by topography and flow down pre-existing river valleys; these produced most of the landforms you will study in the British uplands.

Glacial Systems and Mass Balance

Mass balance (sometimes called the glacial budget) is the relationship between accumulation and ablation over a year, and it is one of the most heavily examined ideas in the topic.

• Accumulation is the input of mass: snowfall, avalanching and wind-deposited snow. Fresh snow is compressed over successive seasons, air is squeezed out, and it recrystallises through firn (névé) into dense glacial ice.
• Ablation is the loss of mass: melting, sublimation, evaporation, calving and avalanching away from the glacier.

The glacier can be divided into two zones. In the upper zone of accumulation, inputs exceed outputs across the year. In the lower zone of ablation, outputs exceed inputs. The boundary between them, where accumulation exactly equals ablation, is the equilibrium line.

Mass balance varies seasonally. A positive balance in winter (more accumulation) tends to advance the snout; a negative balance in summer (more ablation) causes retreat. Over the long term, a sustained negative balance shrinks the glacier and raises the equilibrium line altitude. This is precisely what is happening to most of the world's mountain glaciers today under a warming climate, which links the topic directly to the water cycle and water insecurity. For the climatic and hydrological context, see our Water Cycle and Water Insecurity course.

How Ice Moves

Glacier movement matters because the rate and type of movement controls how effectively a glacier erodes and transports material. Two principal mechanisms operate, and the dominant one depends on whether the glacier is warm- or cold-based.

• Basal sliding occurs in warm-based (temperate) glaciers, where pressure and frictional heat produce a film of meltwater at the base. This lubricates the bed and allows the whole ice mass to slide over the rock. Basal sliding is fast and is associated with vigorous erosion.
• Internal deformation (creep) dominates in cold-based (polar) glaciers, where the base is frozen to the bedrock. Here ice crystals deform and slip past one another under their own weight, and movement is very slow with limited basal erosion.

You should also be able to explain regelation (ice melting under pressure on the upglacier side of an obstacle and refreezing on the downglacier side) and extending and compressing flow (faster, thinning flow on steeper sections; slower, thickening flow where gradient lessens), which control where erosion and deposition concentrate.

Glacial Erosion and Erosional Landforms

Two erosional processes do most of the work:

• Plucking (quarrying) -- meltwater seeps into joints in the bedrock, refreezes onto the glacier, and pulls away loosened blocks as the ice moves. Plucking produces jagged, steep surfaces.
• Abrasion -- rock debris carried at the base of the glacier acts like sandpaper, scratching and smoothing the bedrock. The fine striations and polished surfaces left behind are clear field evidence of former ice direction.

These processes, combined with frost shattering above the ice, generate the classic upland glacial landforms.

Landform	Formation	Field example
Corrie (cwm/cirque)	Armchair-shaped hollow eroded by rotational ice movement, plucking the back wall and abrading the floor; often holds a tarn after deglaciation	Red Tarn, Helvellyn (Lake District)
Arête	Knife-edged ridge where two corries erode back to back	Striding Edge, Helvellyn
Pyramidal peak (horn)	Sharp summit where three or more corries erode towards a common point	Matterhorn (Alps); Snowdon approximates this form
Glacial trough	Pre-existing V-shaped river valley widened, deepened and straightened into a U-shaped valley	Nant Ffrancon, Snowdonia
Hanging valley	Tributary valley left perched above the main trough because the main glacier eroded faster	Numerous in the Lake District and Snowdonia
Ribbon lake	Long, narrow lake occupying an over-deepened section of a trough, often where the ice met softer rock	Wastwater, Lake District
Roche moutonnée	Bedrock knoll with a smooth abraded upglacier (stoss) side and a plucked, steep downglacier (lee) side	Common across glaciated uplands
Truncated spur	Interlocking spur cut off squarely by the powerful main glacier	Lauterbrunnen valley, Switzerland

Note how these landforms cluster into an integrated landscape rather than appearing in isolation -- examiners reward candidates who explain landscapes as assemblages produced by a single ice system.

Glacial Transport and Deposition

Glaciers transport debris in three positions: supraglacial (on the surface), englacial (within the ice) and subglacial (at the base). When the ice melts, this material is deposited largely unsorted, and is collectively called till (or boulder clay).

The principal depositional landforms are:

• Moraines -- accumulations of till. Lateral moraines form along the valley sides; medial moraines form where two glaciers merge and their lateral moraines combine; terminal moraines mark the furthest extent of the ice as a ridge across the valley; recessional moraines mark stillstands during retreat; and ground moraine is the sheet of till spread across the valley floor.
• Drumlins -- streamlined, elongated mounds of till, with a steep blunt stoss end facing the ice and a tapering lee end. Their long axes align with ice flow, making them valuable indicators of former direction. They typically occur in "swarms" producing a "basket of eggs" topography, well displayed in the Eden Valley and parts of the Ribble lowlands.
• Erratics -- boulders transported far from their source and deposited on bedrock of a different lithology. They are powerful evidence of ice movement: Norwegian erratics, for example, are found along the east coast of England, and Lake District rocks have been traced into the Midlands.

Distinguishing unsorted glacial till from sorted fluvioglacial material is a frequent discriminator in the exam, so be precise about it.

Fluvioglacial Processes and Landforms

Meltwater is a hugely effective agent, and fluvioglacial landforms are produced by water flowing from the ice rather than by the ice itself. The key difference from till is that fluvioglacial deposits are sorted (graded by size) and often stratified (layered), because flowing water sorts sediment by energy.

• Outwash plains (sandurs) -- broad, gently sloping spreads of sorted sand and gravel deposited by braided meltwater streams beyond the ice front, fining with distance from the glacier. Iceland's Skeidarársandur is the textbook example.
• Eskers -- long, sinuous ridges of sorted sand and gravel deposited by meltwater streams flowing in tunnels beneath the ice; when the ice melts, the channel deposit is left as a winding ridge.
• Kames -- mounds of sorted material deposited against or within the ice (kame terraces form along valley sides where meltwater ponds between the ice and the valley wall).
• Kettle holes -- depressions, often water-filled, formed where a buried block of ice melts and the overlying sediment collapses into the void.

Periglacial Processes and Landforms

Periglacial environments are cold but largely unglaciated -- the margins of ice sheets, and high latitudes and altitudes today, such as northern Canada, Siberia and the higher Cairngorm plateaux. The defining feature is permafrost: permanently frozen ground. Above it lies the active layer, which thaws each summer and refreezes each winter, driving a distinctive suite of processes.

• Frost heave and frost shattering -- repeated freeze-thaw lifts and sorts stones, producing patterned ground (stone circles, polygons and stripes) and shatters exposed rock into angular blockfields (felsenmeer), well seen on the Cairngorm summits.
• Solifluction -- the slow, lobate downslope flow of the saturated active layer over the impermeable frozen ground beneath, producing solifluction lobes and terraces.
• Nivation -- localised weathering and erosion beneath and around a late-lying snow patch, which can initiate a hollow.
• Pingos -- ice-cored mounds. Open-system (hydraulic) pingos form where groundwater under pressure freezes; closed-system (hydrostatic) pingos form in former lake beds as permafrost advances. They are a striking landform of the Mackenzie Delta in Canada, and degraded relict pingos have been identified in East Anglia.

Relict Glaciated Landscapes in the UK

Britain has no glaciers today, but the uplands are relict landscapes shaped by the Pleistocene ice sheets and valley glaciers. The Lake District is the classic example: radiating glacial troughs, ribbon lakes such as Wastwater and Windermere, corries hosting tarns, the arêtes of Helvellyn, and drumlin fields in the surrounding lowlands together record a former icefield. Snowdonia offers superb troughs such as Nant Ffrancon, hanging valleys, and Cwm Idwal, a corrie whose features helped Darwin and later geologists recognise the former extent of glaciation in Wales.

Be ready to explain that these are relict features: the processes that made them are no longer active in Britain, so present-day change comes from rivers, mass movement and weathering operating on an inherited glacial template. This distinction is a common exam discriminator.

Glaciated and Active Glacial Environments: Value, Threats and Management

The final enquiry question concerns how glaciated environments are used and managed, and you should be able to argue with located evidence.

Value. Glaciated and formerly glaciated areas provide ecosystem services and resources. They store fresh water and regulate downstream river flow, with high mountain glaciers feeding major rivers on which hundreds of millions depend. They also support tourism and recreation (the Lake District and Snowdonia are National Parks), hydroelectric power, and scientific and cultural value. Our Glaciated Landscapes and Change course works through these uses and the management debates in detail.

Threats. Pressures come from climate change, tourism, development and resource extraction. The clearest signal is glacial retreat. In the Alps, the Aletsch Glacier -- the largest in the Alps -- and the Rhône Glacier, which feeds the river of the same name, have retreated markedly over the twentieth and twenty-first centuries, exposing fresh rock and bare moraine. Retreat threatens water supply, alpine tourism economies, and slope stability as newly exposed and thawing ground becomes prone to rockfall and debris flows.

Rapid melting also produces hazards. In Iceland, sub-glacial volcanic eruptions melt ice and release sudden, catastrophic floods called jökulhlaups; the 1996 Grímsvötn–Skeidará event swept across the outwash plain and destroyed sections of the ring road. In the Himalaya, expanding meltwater lakes dammed behind unstable moraine can burst in glacial lake outburst floods (GLOFs), threatening downstream communities and infrastructure in Nepal, Bhutan and the wider region.

Management. Approaches span the sustainability spectrum: conservation designation and zoning in National Parks; honeypot management and footpath restoration to combat erosion in the Lake District; monitoring and early-warning systems for jökulhlaups and GLOFs; and, ultimately, mitigation of climate change to slow glacier loss. In the Swiss Alps, managers have even trialled covering small glacier sections with reflective sheeting to reduce summer ablation. For a UK upland case, the Cairngorms illustrate the tension between conservation, recreation pressure (skiing, the funicular, hill walking) and fragile periglacial and montane habitats.

This management theme links naturally to coastal management debates if your centre also teaches that option; the trade-offs between protection, sustainability and cost recur across both routes. See our Coastal Landscapes and Change course for the comparison.

How to Write Extended Answers on Glaciated Landscapes

Paper 1 mixes short, point-marked questions with longer extended responses (commonly 6-, 8-, 12- and 20-mark items), so calibrate your technique to the tariff.

Match Your Approach to the Assessment Objectives

The longer questions reward all three assessment objectives: accurate knowledge and understanding (AO1), application of that knowledge to the question using located evidence (AO2), and evaluation leading to a justified judgement (AO3). On a 20-mark question, application and evaluation together carry most of the marks, so a description of landforms -- however detailed -- will not reach the top level on its own.

Structure for the Longer Questions

• Introduction -- define the key terms (e.g. mass balance, fluvioglacial) and state the line of argument you will take.
• Main body -- write linked paragraphs, each making one analytical point, supported by specific located evidence (Helvellyn, Skeidarársandur, Aletsch), then explaining and qualifying it. A useful discipline is Point–Evidence–Explain–Link.
• Conclusion -- reach a substantiated judgement rather than repeating points. Phrases such as "the most significant control is..." or "this holds to a large extent because..." signal evaluation.

Typical Questions Worth Practising

• "Assess the relative importance of erosion and deposition in the formation of glaciated landscapes." (requires balanced weighting of processes)
• "Evaluate the view that glacial landforms are best explained by the operation of the glacier as a system." (systems framing)
• "Assess the extent to which climate change is the greatest threat to glaciated environments." (compares threats: climate vs. tourism vs. development)
• "Examine the role of meltwater in shaping glaciated landscapes." (fluvioglacial vs. glacial processes)

Common Mistakes to Avoid

• Confusing till with fluvioglacial deposits. Till is unsorted; outwash, eskers and kames are sorted and often stratified.
• Vague examples. "A glacier in the Alps" is not a case study. "The Rhône Glacier, which has retreated several kilometres since the nineteenth century" is.
• Forgetting the relict point. UK landscapes are inherited; the glacial processes that formed them are no longer active here.
• Listing rather than explaining. Examiners want the process connected to the landform and, on longer questions, an evaluation of its relative importance.

Key Vocabulary for Glaciated Landscapes

Make sure you can define and use these terms accurately:

• Mass balance -- the annual relationship between accumulation and ablation
• Equilibrium line -- the boundary where accumulation equals ablation
• Basal sliding -- movement of warm-based ice over a lubricating meltwater film
• Internal deformation -- slow movement by the deformation of ice crystals in cold-based glaciers
• Plucking and abrasion -- the two principal processes of glacial erosion
• Till -- unsorted material deposited directly by ice
• Fluvioglacial -- relating to landforms produced by glacial meltwater (sorted and stratified)
• Periglacial -- relating to cold, largely unglaciated environments with permafrost
• Permafrost and active layer -- permanently frozen ground and the seasonally thawing surface above it
• Jökulhlaup / GLOF -- sudden glacial outburst floods (volcanic-triggered in Iceland; moraine-dam failure in the Himalaya)
• Relict landscape -- a landscape produced by processes no longer active in that location

Further Revision

For full specification coverage of Glaciated Landscapes and Change with lesson-by-lesson content and AI-powered quizzes, work through our Glaciated Landscapes and Change course. You should also explore the closely related physical topics:

• Coastal Landscapes and Change -- the alternative landscape route, sharing systems thinking and management debates
• The Water Cycle and Water Insecurity -- glacial storage and meltwater are central to drainage basin and global water budgets

Glaciated landscapes reward candidates who think systemically. If you can connect process to landform, and landform to a working ice system under a changing climate, your answers will read as analysis rather than description -- and that is what reaches the top of the mark scheme.