1.1 How can coastal landscapes be viewed as systems

Question 1

Inputs of open systems

Answer 1

-Kinetic energy from wind and waves
-Thermal energy from the heat of the Sun
-Potential energy from the position of material on slopes
-Material from marine deposition
-Weathering and mass movement from cliffs

Question 2

What does Coastal Landscape system mean?

Answer 2

Series of interrelated components and processes that form a whole suite of landforms

Question 3

Outputs of open systems

Answer 3

-Marine and wind erosion from beaches and rock surfaces
-Evaporation

Question 4

Throughputs of open systems

Answer 4

Stores:
-Beach and nearshore sediment accumulations
-Flows (transfers), such as the movement of sediment along a beach by longshore drift

Question 5

What is the state of Coastal Landscape System?

Answer 5

When a system’s inputs and outputs are equal, a state of equilibrium exists within it. In a coastal landscape, this could happen when the rate at which sediment is being added to a beach equals the rate at which sediment is being removed from the beach; the beach will therefore remain the same size.

Question 6

What happens when the equilibrium in the Coastal Landscape is disturbed?

Answer 6

When the equilibrium is disturbed, the system undergoes self-regulation and changes its form in order to restore equilibrium. This is known as dynamic equilibrium, as the system produces its own response to the disturbance and it remains stable over time. This is an example of negative feedback.

Question 7

How can this negative feedback Loop for Coastal Landscapes occur?

Answer 7

• Increased erosion from storms removes beach sediment.
• Less beach means more wave energy hits the backshore/cliffs.
• More cliff erosion adds new sediment to the system.
• Over time, sediment redistributes, rebuilding the beach.
• Eventually, this can restore balance (the beach reforms to protect the coast again), even though the system changed form temporarily.

Question 8

Sediment cells - What are they?

Answer 8

A stretch of coastline and its associated nearshore area within the movement of coarse sediment, sand and shingle is largely self-contained. A sediment cell is a closed system, which suggests that no sediment is transferred from one cell to another.
11 of these around England and Wales coastlines, with a few smaller within these 11

Question 9

Closed system

Answer 9

A system with no inputs or outputs.

Question 10

What is the transfer between sediment cells like in reality? Why?

Answer 10

It is unlikely that sediment cells are completely closed. With variations in wind direction and the presence of tidal currents, it is inevitable that some sediment is transferred between neighbouring cells.

Question 11

What are winds, and what are the effects of stronger/faster winds?

Answer 11

Winds are the movement of air from high to low pressure. Stronger or faster winds generate more energy, leading to larger, more powerful waves with greater erosion potential (more energy transfered to surface of the waves) This increases coastal erosion, sediment transport, and landform development.
NB: The source of energy for coastal erosion and sediment transport is wave action.

Question 12

What are onshore winds, and what do they drive?

Answer 12

Onshore winds are winds that blow from the sea towards the land. They push waves directly toward the coast, Wind also drives aeolian processes (erosion, transport, deposition by air), which help shape features like sand dunes and beaches.

Question 13

What are their effects when winds blow straight on to the coast and at an angle?

Answer 13

increasing their energy and erosive power. If they blow at an angle, they cause waves to approach the shore obliquely, generating longshore drift — the movement of sediment along the coast.

Question 14

What are waves and what energy do they possess?

Answer 14

Waves are the movement of energy through water, usually generated by wind. They have potential energy due to their height above the trough, and kinetic energy from the motion of water particles within the wave.

Question 15

How do waves move, and what examples are there?

Answer 15

waves do not move the water forward, but rather the waves impart a circular motion to the individual water molecules.
A ball floating in the sea is an example of this phenomenon. As a moving wave passes beneath the ball, it rises and falls but does not move horizontally across the water surface.

Question 16

The amount of energy in a wave in deep water formula

Answer 16

P = H²T

P is the power in kilowatts per metre of wave front
H is the wave height in metres
T is the time interval between wave crests in seconds, known as wave period

Question 17

Swell waves

Answer 17

A wave with a long wavelength, low height and steepness. It has a wave period of up to 20 seconds.

Question 18

Storm wave

Answer 18

A wave generated locally by high wind energy. It has a short wavelength, greater height and a shorter wave period.

Question 19

Wave period

Answer 19

The time interval between wave crests in seconds.

Question 20

What are Constructive Waves and what characteristics does it exhibit?

Answer 20

Constructive waves are low-energy waves that build up beaches.

Characteristics:
Strong swash, weak backwash
Low height
Long wavelength
Low frequency (6–9 waves per minute)
Formed in calm weather
Cause deposition, creating wide, gently sloping beaches

Question 21

What are Destructive Waves and what characteristics does it exhibit?

Answer 21

Destructive waves are high-energy waves that erode the coast.
Characteristics:
Weak swash, strong backwash
High height
Short wavelength
High frequency (10–14 waves per minute)
Formed in stormy conditions
Cause erosion, leading to steep, narrow beaches

Question 22

How do constructive waves break and what characteristics can we infer from this?

Answer 22

They usually break by spilling forwards, and the strong swash travels a long
way up the gently sloping beach.
Due to the long wavelength, backwash
returns to the sea before the next wave breaks, and so the next swash
movement is uninterrupted and thus retains its energy.
Gentle Gradient - moves less under gravity

A key feature of
these waves is, therefore, that swash energy exceeds backwash energy

Question 23

How do Destructive waves break and what characteristics can we infer from this?

Answer 23

They tend to break by plunging downwards and so there is little forward transfer of energy to move water up the steeply sloping beach as swash.
Friction from the steep beach slows the swash and so it does not travel far before returning down the beach as backwash. With a short wavelength, the swash of the next wave is often slowed by the frictional
effects of meeting the returning backwash of the previous wave.

In these waves, swash energy is less than backwash energy

Question 24

What is Swash and Backwash?

Answer 24

swash refers to the water that washes up onto a beach after a wave breaks. It’s the forward movement of water up the beach face, often carrying sediment.
Backwash - the receding water from a wave as it flows back down the beach, following the swash (the wave moving up the beach)

Question 25

What are tides and how often do they form?

Answer 25

The periodic rise and fall of the sea surface and are produced by the gravitational pull of the Moon and, to a lesser extent, the Sun. There are 2 high tides and 2 low tides every cycle (roughly 24.5 hours) Larger Variations caused by Spring and Neap tides, that also happen twice each but over 29.5 days (time it takes for moon to orbit earth)

Question 26

How do Tides form?

Answer 26

The Moon’s gravity pulls water towards it, creating a tidal bulge (high tide) on the side of the Earth facing the Moon. A second bulge occurs on the opposite side of Earth due to the centrifugal force as the Earth and Moon orbit their common center of mass. The areas between these bulges experience low tides. As the Earth rotates, different locations pass through these bulges, resulting in two high tides and two low tides roughly every 24 hours and 50 minutes.

Question 27

What are Spring tides? How are they formed and when do they occur?

Answer 27

Spring tides are exceptionally high and low tides that occur when the Sun, Earth, and Moon align, either during a new moon or full moon. Formation: When the Sun and Moon are in alignment, their gravitational forces combine, pulling the Earth’s oceans in the same direction. This results in higher high tides and lower low tides, creating a larger tidal range. During New Moon and Full Moon phases

Question 28

What are Neap tides? How are they formed and when do they occur?

Answer 28

Neap tides are weaker high tides and higher low tides, with a small tidal range. Formation: Neap tides occur when the Sun and Moon are at right angles (90°) to each other, during the first quarter and third quarter moon phases. In this position, the gravitational forces of the Sun and Moon partially cancel each other out, reducing the pull on the Earth’s oceans.

Question 29

Geology

Answer 29

Geology is the study of the Earth’s structure, composition, and processes. It focuses on understanding how the Earth’s materials (like rocks and minerals) and forces (like plate tectonics and erosion) shape the planet’s surface over time

Question 30

Lithology

Answer 30

Describes the physical and chemical composition of rocks.

Question 31

How can Lithology vary between different rocks?

Answer 31

Some rock types, such as clay, have a weak lithology, with little resistance to erosion, weathering and mass movements. This is because the bonds between the particles that make up the rock are quite weak. Others, such as basalt, made of dense interlocking crystals, are highly resistant and are more likely to form prominent coastal features such as cliffs and headlands. Others, such as chalk and carboniferous limestone (predominantly composed of calcium carbonate), are soluble in weak acids and thus vulnerable to the chemical weathering process of carbonation.

Question 32

What is structure and what does it encompass?

Answer 32

The properties and composition of individual rock types such as jointing, bedding and faulting. It also includes the permeability of rocks, such as if it is porous (lets water into the internal structure)

Question 33

How does Porosity of rocks impact erosion?

Answer 33

In porous rocks, such as chalk, tiny air spaces (pores) separate the mineral particles. These pores can absorb and store water - allowing greater chemical weathering, freeze-thaw, and mass movement, making the rock more vulnerable to erosion.

Question 34

With reference to angles what can structure have influence on?

Answer 34

Structure also includes the angle of dip rocks and can have a strong influence on cliff profiles. Both horizontally bedded and landward-dipping strata support cliffs with steep, vertical profile. Where strata incline seawards cliff profiles tend to follow the angle of the dip of bedding planes.

Question 35

Why is structure important regionally?

Answer 35

Structure is an important influence on the planform of coasts at a regional scale. Rock outcrops that are uniform, or run parallel to the coast, tend to produce straight coastlines. These are known as concordant coasts. Where rocks lie at right angles to the coast they create a discordant planform: the more resistant rocks form headlands; the weaker rocks form bays.

Question 36

How does the angle of rock layers (strata) influence cliff profiles?

Answer 36

Horizontally bedded or landward-dipping strata lead to steep, vertical cliffs because the layers are either flat or tilted towards the land. Seaward-dipping strata cause sloping cliffs as the rock layers tilt towards the sea, influencing the cliff’s profile to follow the angle of the dip.

Question 37

What are ocean currents and what do they transfer?

Answer 37

Ocean currents are large-scale water movements driven by Earth's rotation, convection, and winds across the water surface. They transfer heat energy across the globe.

Question 38

How do warm and cold ocean currents differ?

Answer 38

Warm currents move heat from low latitudes to the poles and affect western-facing coastal areas with onshore winds. Cold currents move cold water from the poles to the Equator, driven by offshore winds, and have less impact on coastal landscapes.

Question 39

How do ocean currents affect coastal landscapes?

Answer 39

The strength of the current has a limited direct impact on geomorphic processes, but the transfer of heat influences air temperature, affecting sub-aerial processes like weathering and erosion.

Question 40

How can humans act as a source of coastal sediment?

Answer 40

Beach Nourishment, usually when coastal sediment budget is in deficit. Brought in Lorries and trucks to be dumped and spread out by bulldozers Alternatively Sand and water pumped onshore by pipelines Low Bunds (containers) hold mixture in place while water drains away and leaves sediment behind

Question 41

How can Offshore sources supply sediment?

Answer 41

Marine Deposition via Constructive waves, as well as tides/currents in the same way Wind can blow sediment from other locations, like beaches, but mostly only fine sand as wind has less energy than water so can't transport much

Question 42

What examples of Terrestrial sources of coastal sediment are there?

Answer 42

fluvial deposition, weathering and mass movement, marine erosion, aeolian deposition and longshore drift

Question 43

What is fluvial deposition and how does it contribute to coastal sediment?

Answer 43

Fluvial deposition is the process where rivers deposit sediment as they enter the sea, especially during floods. This material—eroded from inland—adds significantly to the coastal sediment budget

Question 44

What is weathering and how does it supply coastal sediment?

Answer 44

Weathering is the natural process of breaking down rocks in situ via physical, chemical, or biological processes. The resulting debris can be moved by gravity or surface processes to the coast, contributing to sediment supply.

Question 45

What is mass movement and how does it contribute to the sediment budget?

Answer 45

Mass movement is the downslope movement of weathered material under gravity (e.g. landslides, slumping). It delivers sediment directly to the coast, often rapidly and in large volumes.

Question 46

How does marine erosion generate coastal sediment?

Answer 46

Marine erosion by waves erodes cliffs and headlands via processes like hydraulic action and abrasion. Weak cliffs in high-energy environments can supply up to 70% of beach sediment, especially during storm surges or sea level rise.

Question 47

What is aeolian deposition and how does it contribute to coastal sediment?

Answer 47

Aeolian deposition is wind-driven transport and settling of fine sediment, mainly sand, from exposed beaches, dunes, or sand bars. Wind moves smaller particles due to its lower energy compared to water.

Question 48

What is longshore drift and how does it affect sediment supply?

Answer 48

Longshore drift transports sediment along the coast in a zig-zag pattern due to the angled swash and perpendicular backwash. It redistributes sediment between coastal cells, adding to or removing from local budgets.

Question 49

Explain the deposition of sediment in the context of terrestrial

Answer 49

Rivers transport sediment along the course of it and deposit it at the coast River meets sea -> reduction in energy as the forward movement of water is prevented, energy dissipated and the rivers load is deposited Progressive Deposition with larger particles deposited first

Question 50

What is Flocculation and when does it happen?

Answer 50

When fresh water meets saline conditions clay particles clump together due to electrical charges, become heavy and sink Fresh and Salty Water Meeting

Question 51

How do Waves break?

Answer 51

In deep water, waves move in a circular motion with little loss of energy. As waves approach the shore, the water becomes shallower. The wave base (bottom part) drags against the sea floor, slowing down due to friction. The crest (top of the wave) is still moving faster than the base. This causes the wave to steepen and tilt forward. Once the wave’s height exceeds its stability (typically when the wave height is about 1.3 times the water depth), it breaks.

Question 52

What are spilling waves? (referencing what it occurs on, the appearance, energy, and effect of them)

Answer 52

Occurs on: Gently sloping beaches. Appearance: Wave crest spills forward gradually. Energy: Low energy, dissipated over a wide area. Effect: Encourages deposition—builds up wide, gently sloping beaches.

Question 54

What are surging waves? (referencing what it occurs on, the appearance, energy, and effect of them)

Answer 54

Occurs on: Very steep or rocky beaches. Appearance: Wave doesn't break traditionally—slides up the beach. Energy: Very high energy, little water is left behind. Effect: Powerful erosional force, especially on rocky coasts; can undermine structures.