AQA GCSE Geography - Paper 1

Paper 1 - Section B: The Living World + Section C: Coasts

What is a destructive wave?

• A short, steep wave that tend to erode the beach

• Strong backwash & weak swash

What is a constructive wave?

• A long, gentle wave that deposits sediment onto the beach.

• Strong swash & weak backwash

What is mechanical weathering?

The physical breakdown of rocks

What is chemical weathering?

The breakdown of rocks due to chemical reactions

What is mass movement?

The downward movement of sediment, due to gravity and weathering

What is rockfall?

The abrupt movement of rock fragments due to quick erosion

What is a landslide?

Blocks of rock slide downhill when layers of rock dip towards the sea

What is erosion?

Erosion is the removal of material by waves

What is abrasion?

When the sediment in destructive waves are launched at the coast until it wears away

What is attrition?

When sediment within the sea hit each other and breaks down

What is hydraulic action?

When destructive waves crash against the cliff base, compressing air & water into the crack until it weakens/breaks

Describe the formation of caves, arches, stacks and stumps

1. A joint or fault in resistant rock

2. Abrasion and hydraulic action widen the joint to form a cave

3. Waves make the cave larger until it cuts through the headland to make an arch

4. The arch is eroded and the roof becomes too heavy and collapses

5. This leaves a tall stack

6. The stack is eroded and collapses, leaving a stump

What is a wave cut platform?

Narrow flat area found at the edge of a sea cliff.

What is a headland?

Headlands are formed of rocks which are more resistant to erosion, therefore erode more slowly.

What is a bay?

Bays are formed when erosion erodes the softer, less resistant rocks more quickly.

What is deposition & what causes it?

When waves lose their energy and drops sediment at the coastline

Causes:

• Wave type: constructive waves deposit more

• Wind speed: lower wind speed reduces wave energy, depositing more

What are spits?

Spits are piles of sand that create sheltered zones on the coast.

What are bars?

A bar is created when a spit grows across a bay. Lagoons are often created behind a bar.

What are sand dunes?

Sand dunes are hills of sand created at the back of the beach.

What is longshore drift? (+ describe the process)

The movement of sediment along a coastline by wave action

1. Waves approach the coast at an angle.

2. Swash carries sediment up the beach at an angle.

3. Backwash carries sediment down the beach with gravity – perpendicular to the beach.

4. This creates a zig-zag movement of sediment along the beach.

What is managed retreat?

The controlled flooding of coastal areas by removing existing defences 

What are the advantages of managed retreat?

Managed retreat protects the land behind the mangroves or swamps. Managed retreat costs no money & no maintenance is needed. Swamps and mangroves are often biodiverse. Managed retreat moves the coastline. Because of this, it can be called coastal realignment.

What are the disadvantages of managed retreat?

Land is lost to the sea. Some people may lose their land or livelihoods if farmland is allowed to be flooded. Someone's house could be lost if they lived in the area that would become marshland.

Dorset Coastline - mini case study

Located in South-East England with lots of erosional & depositional landforms - contains both concordant & discordant coastlines

1. Erosional: Swanage Bay (headland and bay)

What is a sea wall?

Concrete or rock barrier against the sea placed at the foot of the cliff, usually curved.

What is a groyne?

Timber or rock structures built out to sea from the coast. They trap sediment being moved by longshore drift and enlarge the beach.

What is rock armour?

Piles of large boulders dumped at the foot of a cliff.

What are gabions?

Wire cages filled with rocks that can be built up to support a cliff.

What is beach nourishment?

The addition of sand to an existing beach to make it higher or wider.

What is dune regeneration?

Action taken to build up dunes and increase vegetation.

What is dune fencing?

Construction of fences along the seaward face of the dune to reduce wind speed.

How do waves form?

1. Wind makes contact with the sea, causing ripples

2. Ripples turn into waves

• (in deep water) water molecules in wave move circularly, until increasing contact with sea bed causes crest to curve & break

Explain an example of mechanical weathering

Freeze thaw weathering:

1. Water enters crack in rock

2. It freezes & expands (due to trapped bubbles), widening the crack

3. Repeats until rock splits

Explain an example of chemical weathering

Acid rain:

• Carbonic acid in the rain breaks down & dissolves rock over time

What is slumping?

Occurs in areas of permeable and impermeable layers of rock

How is a wave cut platform formed? (4 main points)

1. Destructive waves erode base of cliff, forming wave-cut notch

2. Height of wave-cut not determined by high/low tides

3. Overhang cracks (due to weathering) & falls off

4. Process repeats & wave-cut platform formed on sea floor where the cliff originally was

How & where are headlands and bays formed? (4 main points)

• Formed by erosion at discordant coastlines

  1. The hard rock remains standing, forming a headland

  2. The soft rock erodes away, forming a bay

  3. A beach is formed in the bay as waves lose energy & deposit material

How & where do caves form into arches to stacks to stumps? (5 main points)

• In hard rock headlands

1. Hydraulic action & abrasion causes a crack in the headland, widening into a cave

2. The cave erodes until there is a gap all the way through the headland, forming the arch

3. The roof of the arch falls, becoming a stack

4. Stumps are smaller, eroded stacks

What are the 2 types of beaches ?

Sandy & shingle beaches

How do sandy beaches form? + Describe 2 characteristics

In sheltered bays:

• Swash is greater than backwash so constructive waves deposit slowly

• Gentle slope & wide beach width

How do shingle (pebble) beaches form? + Describe 2 characteristics

At exposed parts of the coastline:

• Backwash is greater than swash, so destructive waves wash away finer sand, leaving large pebbles

• Steep slope + narrow beach width

How are sand dunes formed? + Outline its 5 main stages

1. Embryo dune - newly formed dune close to sea

2. Fore dune- marrow grass takes hold as embryo dune grows

3. Yellow dune- larger dune with yellow sand

4. Grey dune - more biodiversity & roots hold sand in place

   • Dune slack forms where dune hollows out below water level

5. Mature dune - climatic climax is reached and full ecosystems form

How are spits formed?

1. Longshore drift carries sediment along a coastline in the direction of prevailing winds

2. Spit forms when: coastline changes shape OR longshore drift meets an estuary

3. Material is deposited & spit grows until material is removed faster than deposition

   • Salt marsh behind spit forms - sheltered area causes deposition

How is a bar formed?

Old bay becomes lagoon as longshore drift carries sediment straight across bay

What are 4 examples of hard engineering strategies (+ outline what they are)

• Sea walls - concrete walls at beaches that are physical barriers to the sea

• Rock armour - Large rocks highly resistant to erosion that absorb wave energy

• Gabions - Permeable cages of rock that absorb wave energy

• Grognes - wooden/rock structures that interrupt longshore drift

What are 2 pros and 2 cons of hard engineering strategies?

Pros:

• Effective at reducing erosion/flooding

• Long-term solution

Cons:

• High set-up & maintenance costs

• Can harm ecosystems & habitats

What are 3 soft engineering strategies? (+ outline what they are)

• Beach nourishment - Piling sediment from the sea floor onto the beach to replace eroded sediment

• Beach reprofiling - Mechanically moving around sediment to create high ridges in sand to absorb wave energy

• Dune regeneration- planting xerophytes into sand dunes to create natural barrier

What are 2 pros and 2 cons of soft engineering strategies?

Pros:

• Environmentally friendly

• More aesthetic to locals & tourists

Cons:

• Short term solutions

• Less effective in severe weather

What is managed retreat?

Controlled flooding of low-lying coastal areas

What are 2 pros and 2 cons of managed retreat?

Pros:

• Creates natural habitats

• Cheaper than sea defences

Cons:

• Land & property are lost

• Landowners need to be compensated

What is the name of a UK coastal management scheme?

Lyme Regis Improvement Scheme

Why was coastal management needed in Lyme Regis? (3 reasons)

1. Geology - clay is prone to erosion

2. Threat to homes/businesses - built on unstable cliffs

3. Area’s reliance on tourism - summer population increase from 4k to 15k

What strategies were used for Lyme Regis (+ total cost)

4 phases - £43 million total (completed in 2015):

1. Sea wall near river Lym

2. Rock armour at the Cobb

3. Cancelled as cons outweighed pros

4. New sea wall for extra protection

What are 2 pros and 2 cons of the Lyme Regis Improvement Scheme?

Pros:

• Improved tourism → better beaches & protected harbour

• Area protected from sea storms

Cons:

• Complaints that sea defences ruin natural coastline

• Erosion may worsen in other areas of coast

What is an ecosystem?

= a natural system where plants & animals interact with each other and their environment

What are the 2 main components of an ecosystem?

1. Biotic components - living components of an ecosystem

2. Abiotic components - non-living components of an ecosystem

Give 3 examples of biotic components of an ecosystem

Plants, animals, microorganisms

• ps - dead things are also biotic

Give 3 examples of abiotic components of an ecosystem

Temperature, rainfall, landforms

What are the 4 roles in an ecosystem

1. Producers - convert energy from the environment into sugars

2. Primary consumers - animals that gain energy from eating plants

3. Secondary consumers - animals that gain energy from eating each other

4. Decomposers - break down plant/animal material , returning nutrients to the soil

Give 2 examples of each role in an ecosystem

1. Producers - flowers, trees

2. Primary consumers - herbivores: eg. insects, cows

3. Secondary consumers - eagles, lions

4. Decomposers - bacteria, worms

What is the nutrient cycle?

= the circulation of nutrients between the biotic elements of an ecosystem

Explain the 3 main stages of the nutrient cycle

1. Producers take up nutrients for growth
2. consumers eat producers and use their nutrients for energy & growth
3. Producers/consumers die and decomposers break down organic matter into nutrients

What are the main zones of a freshwater pond?

• Pond bottom

• Mid water

• Pond surface

• Pond margin

• Above pond surface

What types of organisms and conditions can be found in different zones of a pond ecosystem?

Pond bottom:

• Conditions: Little oxygen and light.

• Organisms: Decomposers - eg. Water worms

Mid water:

• Organisms: Fish (main predators) + animals that breathe through gills

Pond surface:

• Conditions: Plenty of oxygen and light.

• Organisms: Ducks, tadpoles + animals that breathe through gills, skin, or lungs

Pond margin:

• Conditions: Lots of light and oxygen; plants thrive.

• Organisms: Frogs & insects sheltered by plants.

Above the pond surface:

• Organisms: birds (eg. Kingfishers) + flying insects (eg. dragonflies)

What are the main characteristics of a tropical rainforest?

• Very warm & wet

• Soil isn’t very fertile

• High biodiversity

Describe the 4 layers of the rainforest

1. Emergent: highest layer with trees approx 50M

2. Main canopy: where most life is found that recieves 70% of sunlight

3. Under canopy: contains younger trees competing for light in dark conditions

4. Shrub layer: lowest layer - is dark & dense with small vegetation

How does the nutrient cycle work in the rainforest?

1. Warm & wet conditions allow dead material to rapidly decompose

2. Rich nutrients in the top soil are quickly absorbed by plants

3. Soil is relatively infertile as a result

What are 2 plant adaptations for the tropical rainforest?

• Buttress roots: tall, above-ground roots to absorb top soil nutrients + keep tree stable

• Drip tips: waxy leaves with pointed tips to allow water run off without damaging plant

What case study illustrates deforestation & its effects?

Malaysian rainforest

What are the 3 causes of deforestation in Malaysia?

• Mining for metals/materials

• Construction of dams/pipelines/roads

• Logging to produce timber

• Land for farming

What are the impacts of deforestation in Malaysia?

• Economic development from developing infrastructure (mines, roads etc) - generate foreign income

• Soil erosion: water washing away nutrient dense top soil stops nutrient cycle & makes it infertile

• Climate change: less trees to absorb C02, global warming

Why is the rainforest important? (3 reasons)

• Helps regulate atmospheric composition (by absorbing CO2)

• Provide medicines (eg rosy periwinkle for leukaemia)

• Raw materials (eg timber)

• What are 4 ways to sustainably manage the rainforest?

• Selective logging: most valuable trees removed without damaging others, then replanting

• Conservation: preserving rainforest for science & education

• Ecotourism: small scale tourism that implements natural world

• International agreements: global environmental agreements/pledges

What are the main characteristics of a hot desert?

• Dry & arid (less than 250mm per year)

• Very hot during day, very cold at night

• Sandy stony soils

What are 2 animal/plant species adapted to the desert & how?

• Camel: sat hump to store energy, thick fur for cold nights

• Cactus: waxy layer reduce water loss, spikes provide shade + reduce water loss via transpiration

What case study shows the opportunities and challenges in a desert?

Moroccan Sahara

What are 3 opportunities created in hot deserts?

• Mineral extraction: phosphate in Morocco

• Energy production: CSP enough to power 1 million Moroccan homes

• Tourism: Atlas Studios located in Sahara - sets for movies

What are 3 challenges created by hot deserts?

• Harsh temperatures: hard to live and work in this

• Lack of water: water supplies can are unreliable (eg reliance on underground wells)

• Inaccessibility: limited road networks to the Sahara, making transport expensive

What is desertification?

= the spread of desert conditions in arid regions due to human activities, drought and climate change

What are some causes of desertification ?

• Climate change: global warming

• Overgrazing: increase in farming leaving soil exposed to Ericsson

• Population growth: places strain on resources (eg water, wood)

What are 3 ways to reduce desertification?

• Planting more trees: holds soil together & reduces soil erosion

• Replace grazing animals with crops: prevents overgrazing

• Appropriate technology: eg earth dams to store water during wet season