physical landscapes

How diverse is the landscape of the UK? (1)

The landscape of the UK varies significantly. For example, there are spectacular mountain ranges in Scotland, rolling hills and valleys in many central and southern areas and extensive flat plains in East Anglia.

How diverse is the landscape of the UK? (2)

The physical geography of the UK was formed through geological, fluvial, glacial, erosional and tectonic processes. As a result, there is a vast range of exposed rock types in the UK, which helps explain our varied scenery of uplands and lowlands.

Where are the UK’s uplands?

The majority of the UK’s upland areas are located in the north and west of the country. These areas are mainly formed from igneous (volcanic) and metamorphic rock.

What aspects of the UK uplands should be considered?

Rock formation, limestone formation and asymmetrical ridges

UK uplands: rock formation

Tough igneous and metamorphic rocks, such as granite and slate, form most of the mountains, such as the Grampians and the north-west Highlands in Scotland and the Lake District in northwest England.

UK uplands: limestone formation

Resistant limestone (a sedimentary rock) forms the backbone of England – the Pennines.
In the southwest, ancient granite (an igneous rock) forms Dartmoor and Bodmin Moor.

UK uplands: asymmetrical ridges

Bands of chalk and limestone (sedimentary rocks) form extensive asymmetrical ridges called escarpments in southwest England, including the Chilterns, the Cotswolds and the North and South Downs.

Where are the UK’s lowlands?

Lowlands are typically found around the coast and in the south and east. These areas are mainly made up of sedimentary rock.

What aspects of UK lowlands should be considered?

Agricultural plains, vales, rift valleys

UK lowlands: agricultural plains

Much of East Anglia and Lincolnshire is made up of weak sedimentary clays, forming flat agricultural plains.

UK lowlands: vales

Broad valleys, known as vales, occur throughout southern England in between limestone
and chalk escarpments.

UK lowlands: rift valley (1)

A rift valley formed by the downward slippage of rock between two faults has created the Central Lowlands of Scotland.

UK lowlands: rift valley (2)

The landform was caused by the downwards slippage of rock in between the Highland Boundary Fault to the north and the Southern Uplands to the south, many lowland areas correspond with river valleys, including the Thames, Severn and Trent.

Where are the UK’s river systems?

The UK has extensive river systems. Most rivers have their source in upland areas and form large river basins. These are large areas of land drained by a river and its tributaries.

What is the longest river in the UK?

At 352 km, the longest river in the UK is the River Severn, which has its source in the Cambrian Mountains in Wales. The River Thames is a close second at 344 km.

What are waves?

Waves are a disturbance on the surface of the sea or ocean in the form of a moving ridge or swell.

How are waves caused? (1)

Waves are caused by energy transfer from the wind to the sea (not to be confused with tides that the Moon causes). As the wind blows over the surface of the sea, it creates friction forming waves.

How are waves caused? (2)

In deep water, water molecules within a wave move in a circular movement. It is only in shallow areas that the water itself moves forward, which occurs along the coastline where the land meets the sea.

Why are some waves stronger than others?

Wave size, wind speed, water density

Why are some waves stronger than others: wave size

The size of a wave depends on its fetch. The fetch of a wave is the distance it travels. The greater the fetch, the larger the wave.

Why are some waves stronger than others: wind speed

Wind speed also has a significant effect on the size of waves. The stronger the wind, the larger the wave because of the energy transfer. Finally, wind duration also affects the size of a wave. The longer the wind blows over the sea or ocean, the larger the wave.

Why are some waves stronger than others: water density

As waves move into shallow water, they begin to stack up as frictional drag with the seabed increases, the base of the wave is slowed down, so the top part is travelling faster causing the wave to tilt, break and move towards the shore in the surf zone

What do constructive/destructive waves do?

Constructive waves build beaches and destructive waves destroy beaches

When are these waves more common?

These waves are more common in summer than in winter.

In what weather conditions do constructive/destructive waves predominate?

Constructive waves predominate in calmer weather conditions when less energy is transferred to the water, destructive waves are more common in winter than in summer and are usually found in more exposed areas.

How tall is each constructive wave?

Each wave is low.

What happens as the constructive wave breaks?

As the wave breaks, it carries material up the beach in its swash.

How is beach material deposited?

Beach material is deposited as the backwash soaks into the sand or slowly drains away.

What happens when the next constructive wave breaks?

When the next wave breaks, its swash will deposit more material without it being 'captured' by the backwash of the preceding wave.

What kind of wavelength and frequency do constructive waves have?

Constructive waves have a long wavelength and a low frequency (8-10 waves per minute).

How tall are constructive waves typically?

They are low and typically under one metre in height.

What is the slope of the wavefront in constructive waves?

The wavefront is gently sloping and gains a little height.

What does the constructive wave do when it breaks?

The wave breaks and spills onto the beach, and water spreads a long way up the gently sloping beach.

Where are constructive waves typically found?

Constructive waves are typically found in sheltered bays and spits, building up sandy beaches.

Compare the swash and backwash in constructive and destructive waves (1)

As destructive waves approach the coast, they gain height, plunge onto a steep beach, and do not travel far up it. The swash is very weak, whereas the backwash is strong. This leads to a net loss of beach material.

Compare the swash and backwash in constructive and destructive waves (2)

Although a destructive wave’s swash is much stronger than a constructive wave, its backwash is much weaker than its swash. These waves can transport beach material back into the sea, creating a steep beach profile.

How tall are destructive waves typically

The waves are usually very high, have a short wavelength and are very frequent. They have a steep front and are typically over 1 metre tall.

What can the force of destructive waves lead to?

The force generated by a destructive breaking wave can erode a headland.

What is weathering?

In coastal geography, weathering plays a crucial role in shaping coastlines. It refers to the breakdown of rocks and minerals along the shore caused by different environmental forces.

What are the three main types of weathering?

mechanical, chemical, and biological

What are the types of mechanical weathering?

Physical/mechanical weathering, thermal expansion and freeze thaw weathering

Describe Mechanical Weathering (Physical Weathering) (1)

Mechanical weathering involves the breakdown of rocks into smaller pieces without changing their chemical composition. Physical forces drive this process, typically the effects of temperature changes, water, and wind.

Describe Freeze-thaw Weathering (1)

Freeze-thaw weathering occurs when water enters cracks in rocks. When the temperature drops, the water freezes and expands. This expansion puts pressure on the rock, causing it to crack further.

Describe Freeze-thaw Weathering (2)

When the temperature rises, the ice melts, and the cycle repeats. Over time, this process weakens the rock, causing it to break apart. Freeze-thaw weathering is particularly common in coastal areas where temperatures fluctuate around freezing.

Describe thermal expansion (1)

Rocks expand when heated by the sun and contract as they cool. This constant expansion and contraction, especially in areas with large temperature variations between day and night, can cause the rock to fracture and break into smaller pieces.

Describe thermal expansion (2)

Coastal rocks exposed to the sun during the day and cool at night are particularly vulnerable to this process.

What are the types of chemical weathering?

Chemical weathering, hydrolysis, carbonation and oxidation

Describe Chemical Weathering

Chemical weathering occurs when rocks break down due to chemical reactions, altering their mineral composition. This type of weathering is common in coastal environments, especially in areas with high rainfall levels or saltwater exposure.

Describe hydrolysis (1)

Hydrolysis happens when minerals in the rock react with water, causing them to break down and form new minerals. This process can weaken rocks over time.

Describe hydrolysis (2)

For example, feldspar in granite can react with water to form clay minerals, softening the rock and making it more susceptible to further weathering.

Describe carbonation (1)

Carbonation occurs when carbon dioxide (CO₂) from the air dissolves in rainwater to form carbonic acid. This weak acid reacts with limestone and other calcium carbonate-rich rocks, dissolving them and creating cavities or larger features like caves.

Describe carbonation (2)

Saltwater in coastal environments can accelerate this process, especially in areas with limestone.

Describe oxidation (1)

Oxidation occurs when minerals containing iron, such as sandstone or shale, react with oxygen in the air or seawater. This reaction leads to the formation of iron oxide, which weakens the rock and often changes its colour to a reddish or brownish hue.

Describe oxidation (2)

Oxidation is particularly noticeable in coastal regions where exposure to oxygen-rich seawater accelerates the process.

What are the impacts of Weathering on Coastal Landscapes?

Collapse, wave cut platform destruction and caves/arches/stacks

Impacts of weathering on coastal landscapes: collapse

Cliffs become more prone to collapse as weathering processes weaken the rock structure.

Impacts of weathering on coastal landscapes: wave cut platform destruction

Wave-cut platforms form as the base of a cliff is eroded by the combined action of weathering and wave erosion.

Impacts of weathering on coastal landscapes: caves/arches/stacks

Caves, arches, and stacks can form when weathering processes create weaknesses in the rock, which wave action exploits.

What is Mass Movement?

Mass movement is the downhill movement of rock and soil under the force of gravity.

Why is mass movement significant?

It plays a significant role in shaping coastal landscapes by transporting eroded material down cliffs and onto the shoreline.

What are the four main types of mass movement?

Rockfalls, landslides, mudslides and slumping

What is slumping

Slumping occurs on cliffs composed of soft materials, such as boulder clay, often left behind by glaciers. These cliffs are vulnerable to both marine and subaerial processes.

How does slumping happen? (1)

Rainwater infiltrates and saturates the permeable clay, increasing its weight, waves erode the base of the cliff through hydraulic action and abrasion, forming a wave-cut notch, a slip plane forms as the saturated material becomes unstable.

How does slumping happen? (2)

The heavy clay slumps downward in a rotational motion along a curved slip plane, the slumped material flows onto the beach, creating a bulging toe at the base of the cliff.

Example of slumping

The Holderness Coast is Europe’s fastest-eroding coastline. Here, slumping is common due to the soft boulder clay cliffs. Water will percolate down the large crack to lubricate the slip plane. This will cause the cliff to slump further down.

What are landslides?

Landslides involve large sections of cliff moving rapidly downhill along a straight slip plane. They often occur on cliffs made of resistant rock, such as sandstone or limestone, and are usually triggered by erosion and heavy rainfall.

Describe the erosion process and wave cut notch formation with landslides

In areas of more resistant cliff material, erosion is most significant when waves break at the foot of a cliff. This causes erosion at the base of the cliff. This creates a wave-cut notch in the base of the cliff.

What are the consequences of landslides and wave cut platforms?

As the notch increases in size, the weight of the cliffs above becomes too much to support, leading to a landslide. This material will provide temporary protection for the cliff behind. However, once the sea has removed it, this process will occur again. Wave-cut platforms will be created where cliffs are made of more resistant material.

How do landslides happen? (1)

Marine erosion at the base of the cliff (especially hydraulic power and abrasion) forms a wave-cut notch, removing support. Rainwater infiltrates the rock, adding weight and reducing internal cohesion.

How do landslides happen? (2)

A straight slip plane develops as gravity pulls the weakened rock downward. The rock mass slides rapidly down the cliff face in large slabs. The fallen material accumulates at the base, temporarily protecting the cliff until it is removed by wave action.

Example of a landslide

In West Bay on the Jurassic Coast in Dorset, a large landslide occurred in 2012 following heavy rainfall. The sandstone cliff collapsed suddenly, blocking a coastal path and highlighting the risk of slope instability in resistant rock cliffs. The image below shows a landslide at West Bay, Dorset.

What is rockfall?

Rockfall occurs when fragments of rock break away from the cliff face and fall vertically or bounce down the slope. This is most common on steep or vertical cliffs composed of hard, jointed rock, such as limestone.

How do rockfalls happen? (1)

Weathering processes, especially freeze-thaw, widen joints and cracks in the rock, water enters cracks during the day and freezes overnight, expanding and putting pressure on the surrounding rock, repeated cycles of freezing and thawing weaken the rock structure.

How do rockfalls happen? (2)

Eventually, rock fragments detach and fall under gravity. The fallen material collects at the foot of the cliff to form a scree slope or debris pile.

Example of a rockfall

At Port Mulgrave on the Yorkshire coast, frequent rockfalls have occurred due to freeze-thaw weathering acting on the exposed rock face. These events pose risks to coastal paths and access points.

What is a mudslide?

Mudslides involve the rapid downhill movement of saturated soil and weak rock, typically in the form of a flowing slurry. They often occur after heavy rainfall, particularly on cliffs made of boulder clay or other unconsolidated materials.

How do mudslides happen? (1)

Prolonged or intense rainfall saturates the loose soil and weak rock on a slope. As the water content increases, the material becomes heavier and less stable. The slope fails suddenly, and the saturated material begins to move.

How do mudslides happen? (2)

The mixture of soil and water flows downhill rapidly, following the natural gradient. The moving material forms a bulging, lobe-shaped deposit at the base of the slope or cliff.

Example of a mudslide

At Mappleton on the Holderness Coast, mudslides are common due to the cliff’s composition of glacial boulder clay. Heavy rainfall often triggers rapid movement of saturated material, threatening roads and property along the coast.

What is coastal erosion?

Coastal erosion is the wearing away of land by the sea, often involving destructive waves that erode the coast (though constructive waves also contribute to coastal erosion).

What are the four main processes of coastal erosion?

There are four main processes of coastal erosion. These are corrasion, abrasion, hydraulic action and attrition.

Processes of coastal erosion: corrasion

Corrasion is when destructive waves pick up beach material (e.g. pebbles) and hurl them at the base of a cliff. Over time, this can loosen cliff material, forming a wave-cut notch.

Processes of coastal erosion: abrasion

Abrasion occurs as breaking waves, concentrated between the high and low watermarks, which contain sand and larger fragments that wear away the base of a cliff or headland. It is commonly known as the sandpaper effect. This process is widespread in high-energy storm conditions.

Processes of coastal erosion: hydraulic action (1)

Waves hitting the base of a cliff cause air to be compressed in the cracks, joints, and folds of bedding planes, resulting in repeated changes in air pressure. As air rushes out of the cliff when the wave retreats, it leads to an explosive effect as pressure is released.

Process of coastal erosion: hydraulic action (2)

This process is supported further by the weakening effect of weathering. The material breaks off cliffs, sometimes in huge chunks. This process is known as hydraulic action.

Processes of coastal erosion: attrition

Attrition is when waves cause rocks and pebbles to bump into each other and break up.

What factors affect the rate of coastal erosion? (1)

Waves have a large fetch, e.g. the south-west coast has an 8000 kilometre fetch across the Atlantic Ocean, strong winds blow for a long time, creating destructive waves, an area of coastline has no beach to buffer the waves;

What factors affect the rate of coastal erosion? (2)

The cliff material is soft, e.g. soft boulder clay along the Holderness Coast means it experiences the highest rate of erosion in Europe, cliffs made from rock have many joints, a headland sticks out into the sea, and waves converge on it (wave refraction).

What is longshore drift?

Longshore (littoral) drift is the movement of material along the shore by wave action. It happens when waves approach the beach at an angle.

Describe the process of longshore drift (1)

The swash (waves moving up the beach) carries material up and along the beach. The backwash (waves moving back down the beach) carries material back down the beach at right angles.

Describe the process of longshore drift (2)

This is the result of gravity. This process slowly moves material along the beach and provides a link between erosion and deposition.

Landforms created by longshore drift

Longshore drift contributes towards the formation of a range of depositional landforms such as spits and onshore bars. For example, spurn Point is a coastal spit formed by the transportation of coastal sediment by longshore drift along the Holderness Coast. This material is then deposited at the mouth of the Humber Estuary.

What is coastal transportation?

Coastal transportation is the movement of material in the sea and along the coast by waves. The movement of material along the coast is called longshore drift.

Although longshore drift is the main process of transportation, what are the four ways material moves?

Traction, saltation, suspension, solution

Processes of coastal transportation: traction

Traction involves large pebbles and boulders being rolled along the seafloor. High-energy destructive waves are most likely to transport material by traction.

Processes of coastal transportation: saltation

Saltation involves small stones, pebbles, and silt being bounced along the seafloor. Both destructive and constructive waves can move this smaller material by saltation.

Processes of coastal transportation: suspension

Transportation by suspension is when fine particles of clay and sediment are suspended in the sea and transported by both destructive and constructive waves.

Processes of coastal transportation: solution

When material is dissolved and carried by the sea, it is transported in solution.

What is a landform?

A landform is a feature of the landscape that has been formed or sculpted by processes of: erosion, transportation or deposition

What are the two key factors in shaping landforms along the coastline?

Geological structure and rock type