AQA A-level Geography · 3.1.3

Coastal systems and processes

50 exam-style questions with answers for 3.1.3 Coastal systems and processes in AQA A-level Geography (spec 7037). Practise with flashcards, a topic quiz, a random quiz across the course, 5 crosswords, or read every question and answer below. Not official AQA material.

All 50 questions and answers

Question 1 · Spec 3.1.3.1 · Coastal systems
Describe the main inputs, stores, flows and outputs of a coastal system. [4 marks]
Answer:
Inputs: waves, wind, tides, currents and sediment from rivers and cliffs (1); stores: beaches, dunes, spits, offshore bars and the sea (1); flows: longshore drift and onshore and offshore transfers of sediment (1); outputs: sediment lost offshore to deeper water or out of the cell (1).
Question 2 · Spec 3.1.3.1 · Coastal systems
Explain why a coastal system is an open system. [2 marks]
Answer:
Energy and matter cross its boundaries (1); waves, wind and sediment enter, and sediment and water leave the system (1).
Question 3 · Spec 3.1.3.1 · Coastal systems
Explain how a beach can be in dynamic equilibrium. [3 marks]
Answer:
Storms with destructive waves remove sand from the beach (1); calmer periods with constructive waves return it (1); the beach changes shape through the year but its average profile remains stable (1).
Question 4 · Spec 3.1.3.1 · Coastal systems
Explain how negative feedback operates between a beach and a cliff. [3 marks]
Answer:
A wide beach absorbs wave energy, so less erodes the cliff (1); if the beach shrinks, more energy reaches the cliff and erosion increases (1); cliff erosion supplies sediment that helps to rebuild the beach, restoring protection (1).
Question 5 · Spec 3.1.3.1 · Coastal systems
Explain how positive feedback may operate in a sand dune system. [3 marks]
Answer:
Trampling or storm damage removes vegetation from part of a dune (1); wind erodes the exposed sand and forms a blowout (1); the blowout widens, destroying more vegetation and speeding erosion (1).
Question 6 · Spec 3.1.3.1 · Coastal systems
Distinguish between a landform and a landscape at the coast. [2 marks]
Answer:
A landform is an individual feature, such as a spit or a stack (1); a landscape is the overall appearance of an area formed by related landforms, such as a cliffed coast with platforms (1).
Question 7 · Spec 3.1.3.2 · Energy
Distinguish between high-energy and low-energy coasts. [2 marks]
Answer:
High-energy coasts have strong waves, large fetch and rapid erosion, with cliffs and platforms (1); low-energy coasts are sheltered with small waves, so deposition dominates, forming beaches, mudflats and saltmarshes (1).
Question 8 · Spec 3.1.3.2 · Energy
Define fetch and explain why it matters. [2 marks]
Answer:
The distance of open water over which the wind blows (1); a longer fetch produces larger waves with more energy (1).
Question 9 · Spec 3.1.3.2 · Energy
Explain how waves are formed and break on the coast. [3 marks]
Answer:
Wind blowing over the sea creates friction and transfers energy to the water, forming waves (1); as waves enter shallow water, friction with the sea bed slows the base while the top moves faster (1); the wave becomes steeper and breaks onto the shore (1).
Question 10 · Spec 3.1.3.2 · Energy
Distinguish between swash and backwash. [2 marks]
Answer:
Swash is the movement of water up the beach after a wave breaks (1); backwash is the return flow of water down the beach under gravity (1).
Question 11 · Spec 3.1.3.2 · Energy
Describe the characteristics of constructive waves. [3 marks]
Answer:
Low height and long wavelength (1); low frequency, around 6 to 8 waves per minute (1); strong swash and weak backwash, so they build up beaches (1).
Question 12 · Spec 3.1.3.2 · Energy
Describe the characteristics of destructive waves. [3 marks]
Answer:
High and steep with a short wavelength (1); high frequency, around 10 to 14 waves per minute (1); strong backwash and weak swash, so they remove material from beaches (1).
Question 13 · Spec 3.1.3.2 · Energy
Explain how currents transport sediment at the coast. [2 marks]
Answer:
Longshore currents flow parallel to the shore when waves approach at an angle and carry sediment along the coast (1); rip currents flow seawards and carry sediment offshore (1).
Question 14 · Spec 3.1.3.2 · Energy
Explain how tides are caused and how spring and neap tides differ. [3 marks]
Answer:
Tides are caused by the gravitational pull of the Moon and Sun on the oceans (1); spring tides have the largest range when the Sun, Moon and Earth are aligned (1); neap tides have the smallest range when the Sun and Moon are at right angles (1).
Question 15 · Spec 3.1.3.2 · Energy
Define tidal range. [1 mark]
Answer:
The vertical difference in height between high tide and low tide.
Question 16 · Spec 3.1.3.2 · Energy
Explain how tidal range affects coastal processes. [2 marks]
Answer:
A large tidal range spreads wave attack over a wider vertical zone of the shore, with strong tidal currents in estuaries (1); a small tidal range concentrates wave energy on a narrow zone, increasing local erosion (1).
Question 17 · Spec 3.1.3.2 · Energy
Explain how a storm surge affects the coast. [2 marks]
Answer:
Low atmospheric pressure and strong onshore winds raise sea level locally (1); waves attack higher up the shore, increasing erosion and the risk of coastal flooding (1).
Question 18 · Spec 3.1.3.2 · Sediment cells
What is a coastal sediment cell? [2 marks]
Answer:
A length of coastline and its associated seabed in which sediment movement is largely self-contained (1); with sources, transfers and sinks, bounded by features such as headlands (1).
Question 19 · Spec 3.1.3.2 · Sediment cells
Name four sources of coastal sediment. [4 marks]
Answer:
Any four from: rivers (1); erosion of cliffs (1); the sea bed (1); longshore drift from adjacent areas (1); wind-blown sand (1); beach nourishment by humans (1).
Question 20 · Spec 3.1.3.2 · Sediment cells
Name two sediment sinks in a coastal cell. [2 marks]
Answer:
Any two from: beaches, spits and bars (1); estuaries, mudflats and saltmarshes (1); offshore sand banks and the deep sea bed (1).
Question 21 · Spec 3.1.3.2 · Sediment cells
Define a sediment budget. [2 marks]
Answer:
The balance between sediment entering and leaving a coastal cell (1); a positive budget builds up beaches and landforms, a negative budget leads to erosion (1).
Question 22 · Spec 3.1.3.2 · Sediment cells
A cell receives 12,000 m³ of sediment from cliffs and 8,000 m³ from rivers. 15,000 m³ is lost offshore. Calculate the net sediment budget. [2 marks]
Answer:
Inputs 20,000 − outputs 15,000 (1); = +5,000 m³, a positive budget (1).
Question 23 · Spec 3.1.3.2 · Sediment cells
Explain how coastal defences can alter the sediment budget. [3 marks]
Answer:
Groynes trap sediment on one side, starving beaches further along the coast (1); sea walls prevent cliff erosion, cutting off a sediment source (1); less sediment reaches downdrift areas, increasing erosion there (1).
Question 24 · Spec 3.1.3.2 · Sediment cells
Explain why coastal sediment budgets vary seasonally. [2 marks]
Answer:
Winter storms bring destructive waves that remove sand and shingle from beaches (1); calmer summer conditions bring constructive waves that rebuild them (1).
Question 25 · Spec 3.1.3.2 · Weathering
What is meant by sub-aerial processes at the coast? [1 mark]
Answer:
Processes that act on the land surface above the high tide mark, such as weathering, mass movement and runoff.
Question 26 · Spec 3.1.3.2 · Weathering
Explain how freeze-thaw weathering operates on coastal cliffs. [3 marks]
Answer:
Water enters cracks in the rock (1); at freezing, the water expands by about 9% and exerts pressure (1); repeated freezing and thawing widens cracks until pieces break off (1).
Question 27 · Spec 3.1.3.2 · Weathering
Explain how salt crystallisation weathers coastal rocks. [2 marks]
Answer:
Sea spray enters pores and cracks in rock, and water evaporates, leaving salt crystals (1); the crystals grow and exert pressure, which breaks rock apart (1).
Question 28 · Spec 3.1.3.2 · Weathering
Explain how carbonation weathers limestone and chalk cliffs. [2 marks]
Answer:
Rainwater absorbs carbon dioxide to form weak carbonic acid (1); the acid reacts with calcium carbonate, dissolving the rock (1).
Question 29 · Spec 3.1.3.2 · Weathering
Describe two forms of biological weathering at the coast. [2 marks]
Answer:
Plant roots grow into cracks and widen them (1); burrowing animals and boring marine organisms, such as piddocks, weaken rocks (1).
Question 30 · Spec 3.1.3.2 · Mass movement
Describe four types of mass movement on coastal cliffs. [4 marks]
Answer:
Rockfall, where fragments fall freely from a steep face (1); rotational slumping, where material slides along a curved surface (1); mudflow, where saturated soil and clay flow downslope (1); landslide, where blocks slide along a flat plane (1).
Question 31 · Spec 3.1.3.2 · Mass movement
Explain how rotational slumping occurs on soft clay cliffs. [3 marks]
Answer:
Heavy rain saturates the clay, adding weight and reducing friction (1); waves undercut the base of the cliff, removing support (1); material slips along a curved slip plane, leaving stepped, back-tilted blocks (1).
Question 32 · Spec 3.1.3.2 · Mass movement
Explain why mass movement is more likely after heavy rainfall. [2 marks]
Answer:
Saturated material becomes heavier and more fluid (1); water reduces friction between particles and along slip planes, so slopes become unstable (1).
Question 33 · Spec 3.1.3.2 · Mass movement
Explain how surface runoff affects cliffs. [2 marks]
Answer:
Water flowing over the cliff erodes channels or gullies (1); it can also carry fine material downslope and saturate cliff material, increasing mass movement (1).
Question 34 · Spec 3.1.3.2 · Erosion
Explain the process of hydraulic action. [2 marks]
Answer:
Waves force water and air into cracks in cliffs (1); pressure is repeatedly compressed and released, weakening the rock and breaking it apart (1).
Question 35 · Spec 3.1.3.2 · Erosion
Explain the process of wave quarrying. [2 marks]
Answer:
The impact of a breaking wave on the cliff exerts a powerful force (1); this dislodges and removes pieces of rock from the cliff face (1).
Question 36 · Spec 3.1.3.2 · Erosion
Explain the process of corrasion (abrasion). [2 marks]
Answer:
Waves pick up sand, pebbles and boulders and hurl them against the cliff (1); the load grinds away rock like sandpaper (1).
Question 37 · Spec 3.1.3.2 · Erosion
Explain the process of cavitation. [2 marks]
Answer:
Air bubbles trapped in the water implode as waves break on rock (1); the shock waves weaken the rock surface and help to fracture it (1).
Question 38 · Spec 3.1.3.2 · Erosion
Define solution (corrosion) at the coast. [1 mark]
Answer:
The chemical dissolving of rock minerals, such as chalk and limestone, by seawater.
Question 39 · Spec 3.1.3.2 · Erosion
Explain the process of attrition. [2 marks]
Answer:
Sediment carried by waves collides and knocks together (1); particles become smaller, smoother and more rounded over time (1).
Question 40 · Spec 3.1.3.2 · Transportation
Describe four ways in which sediment is transported at the coast. [4 marks]
Answer:
Traction: large pebbles roll along the sea bed (1); saltation: smaller particles bounce along the bed (1); suspension: fine particles are carried in the water (1); solution: minerals dissolved in the water are carried (1).
Question 41 · Spec 3.1.3.2 · Transportation
Explain how longshore drift moves sediment along a beach. [4 marks]
Answer:
Waves approach the coast at an angle, driven by the prevailing wind (1); the swash carries sediment up the beach at that angle (1); the backwash returns at right angles to the shore, down the steepest slope (1); this repeated movement transports material along the coast in a zigzag (1).
Question 42 · Spec 3.1.3.2 · Deposition
Explain when and where deposition occurs at the coast. [2 marks]
Answer:
When wave energy and velocity fall, so material can no longer be carried (1); in sheltered areas such as bays, behind headlands and in estuaries, or where sediment supply is high (1).
Question 43 · Spec 3.1.3.2 · Factors
Explain how rock type affects the rate of coastal erosion. [3 marks]
Answer:
Resistant rocks such as granite erode slowly and form headlands and steep cliffs (1); weaker rocks such as clay and sands erode quickly and form bays and gentle slopes (1); permeable rocks such as chalk may be weakened by water but form high cliffs (1).
Question 44 · Spec 3.1.3.2 · Factors
Explain how geological structure affects coastal landforms. [3 marks]
Answer:
Joints, faults and bedding planes are lines of weakness that waves exploit (1); the dip of the strata affects cliff stability and profile (1); features such as caves and arches develop along weaknesses (1).
Question 45 · Spec 3.1.3.2 · Factors
Distinguish between concordant and discordant coastlines. [2 marks]
Answer:
On a concordant coast, bands of rock run parallel to the shore, giving a smooth outline (1); on a discordant coast, they run at right angles, producing alternating headlands and bays (1).
Question 46 · Spec 3.1.3.2 · Factors
Explain how human activity can alter coastal processes. [2 marks]
Answer:
Coastal defences, dredging and building change wave energy and sediment movement (1); removing dunes or vegetation, or damming rivers that supply sediment, increases erosion (1).
Question 47 · Spec 3.1.3.2 · Field data
Describe how a beach profile could be measured in the field. [3 marks]
Answer:
Lay a transect from the top of the beach down to the sea (1); use ranging poles and a clinometer to measure the angle and distance between breaks of slope (1); repeat at several sites or times to compare profiles (1).
Question 48 · Spec 3.1.3.2 · Field data
Describe how the size and shape of beach sediment could be sampled. [3 marks]
Answer:
Use systematic sampling at set intervals along a transect (1); measure the long axis of pebbles with callipers and assess roundness using a scale such as Powers' (1); compare results along the beach to show how processes such as attrition and sorting operate (1).
Question 49 · Spec 3.1.3.2 · Energy
Explain how wave refraction concentrates wave energy on headlands. [3 marks]
Answer:
Waves slow in shallow water off a headland but continue faster in deeper water in bays (1); the wave fronts bend (refract) around the headland (1); energy is concentrated on the headland, causing erosion, while it is dispersed in the bay, where deposition occurs (1).
Question 50 · Spec 3.1.3.2 · Transportation
Distinguish between swash-aligned and drift-aligned beaches. [2 marks]
Answer:
On a swash-aligned beach waves approach parallel to the shore, so there is little longshore drift (1); on a drift-aligned beach waves approach at an angle, so sediment moves along the coast by longshore drift (1).

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