Coasts

Question 1

Why is the coast considered an open system?

Answer 1

The coast is considered an open system because it receives inputs from outside sources and transfers outputs away into other systems, such as terrestrial, atmospheric, and oceanic systems.

Question 2

Which biogeochemical cycles are involved in the coastal system?

Answer 2

The coastal system is involved in the rock cycle, the water cycle, and the carbon cycle.

Question 3

Which external systems interact with the coastal system?

Answer 3

The coastal system interacts with terrestrial, atmospheric, and oceanic systems.

Question 4

Under what circumstances might the coastal system be treated as a closed system?

Answer 4

In specific contexts such as scientific research and coastline management planning, the coastal system is treated as a closed system.

Question 5

How does the coastal system relate to the oceans around the globe?

Answer 5

The coastal system both impacts and is impacted by processes that occur in the five major oceans and the smaller seas they connect with.

Question 6

What types of habitats and activities can be affected by the coastal environment?

Answer 6

Various coastal habitats and human activities are influenced by—and in turn influence—the coastal environment. These can include natural habitats, recreational sites, industrial areas, and ecosystems that rely on coastal conditions.

Question 7

What is a sediment cell?

Answer 7

A sediment cell is a section of coastline, often bordered by prominent headlands, within which the movement of sediment is largely contained. In these cells, sediment flows tend to operate in dynamic equilibrium.

Question 8

Define dynamic equilibrium in the context of a sediment cell.

Answer 8

Dynamic equilibrium in a sediment cell refers to a constant state of change where the sediment inputs and outputs are continuously adjusting but remain in balance. This balance helps maintain the overall form and behavior of the coastal system.

Question 9

How can the dynamic equilibrium in a sediment cell be disrupted?

Answer 9

The dynamic equilibrium can be interrupted in the short term by natural variations (such as storms or tidal changes) or disturbed in the long term by human interventions (including coastal defenses, pollution, settlement, and recreational activities).

Question 10

What are subcells in the context of sediment cells, and why are they important in coastal management?

Answer 10

Within each sediment cell, smaller sections called subcells exist. These subcells are often used during coastal management planning as they help refine the understanding of sediment dynamics at a more localized scale, aiding in targeted management decisions.

Question 11

List the primary input factors to the coastal system found in sediment cells.

Answer 11

Coastal inputs generally fall into three main categories:
Marine: Waves, tides, salt spray.
Atmosphere: Sun, air pressure, wind speed, and wind direction.
Humans: Pollution, recreation, settlement, and defences.

Question 12

What are some of the outputs in the coastal system that affect sediment dynamics?

Answer 12

Outputs include processes that remove material or energy from the system, such as:
Ocean currents
Rip tides
Sediment transfer
Evaporation

Question 13

Identify various stores or sinks in the coastal system where sediment can accumulate.

Answer 13

The coastal system has 16 stores/sinks for sediment, including:
Beaches
Sand dunes
Spits
Bars and tombolos
Headlands and bays
Nearshore sediment
Cliffs
Wave-cut notches
Wave-cut platforms
Caves
Arches
Stacks
Stumps
Salt marshes
Tidal flats
Offshore bands and bars

Question 14

What are transfers/flows in the coastal system, and why are they important?

Answer 14

Transfers/flows are the processes that link the inputs, outputs, and stores in the coastal system. They determine how sediment and energy move within the system, shaping the coastal landscape and influencing coastal management.

Question 15

Name some key processes involved in the transfers or flows of sediment in the coastal system.

Answer 15

Key transfer processes include:
Wind-blown sand
Mass-movement processes
Longshore drift
Weathering
Erosion (via hydraulic action, corrosion, attrition, and abrasion)
Transportation (as bedload, in suspension, by traction, and in solution)
Deposition (through gravity settling and flocculation)

Question 16

What are the four types of erosion processes in coastal environments?

Answer 16

The 4 erosion processes are:
Hydraulic Action: The force of the water striking the coast, breaking down the rock.
Corrosion: Chemical weathering where saltwater dissolves minerals.
Attrition: The gradual breaking down of rocks as they collide with each other.
Abrasion: The wearing away of rock surfaces by the friction of transported sediments.

Question 17

How is sediment transported in coastal systems, and what are the different ways?

Answer 17

Saltation: Sediment rolling or sliding along the seabed.
In Suspension: Fine particles carried within the water column.
Traction: Larger particles pushed or pulled along the bottom by water movement.
In Solution: Materials dissolved in water, later precipitated elsewhere.

Question 18

What are the two main forms of deposition in coastal systems, and how do they work?

Answer 18

The two main deposition processes are:
Gravity Settling: Heavier particles settle out of the water column due to gravity.
Flocculation: Fine particles clump together to form larger aggregates that settle more readily.
These processes enable sediment to accumulate, forming features such as beaches and bars.

Question 19

What types of energy drive the transfers and flows in the coastal system, and why is this energy significant?

Answer 19

The 3 energy sources include:
Wind: Drives the movement of air and induces wave formation and sand transport.
Gravitational: Influences mass movements and longshore drift.
Flowing Water: Powers erosion, transportation, and deposition processes.
This energy is significant because it is the driving force that initiates and sustains the dynamic changes at the coast.

Question 20

What are feedback loops in the coastal system?

Answer 20

Feedback loops are mechanisms within the coastal system that either enhance changes (positive feedback) or balance changes (negative feedback) to move the system away from or back toward dynamic equilibrium.

Question 21

What is a negative feedback loop, and how does it work in a coastal system?

Answer 21

A negative feedback loop lessens any change in the system. For example, after a storm erodes a beach and introduces excess sediment, destructive waves lose energy as sediment is deposited as an offshore bar. This bar dissipates wave energy, protects the beach from continued erosion, and eventually, as the bar is eroded, the system returns to dynamic equilibrium.

Question 22

What is a positive feedback loop in coastal systems, and can you provide an example?

Answer 22

A positive feedback loop amplifies the changes, making the system more unstable. For instance, when people walk over sand dunes, they damage the vegetation that holds the dunes in place. This leads to increased erosion of the dunes, which in turn further exposes the underlying beach, driving the system further away from its original state.

Question 23

How do rivers contribute to sediment input in the coastal zone?

Answer 23

Rivers contribute significant sediment inputs, especially in high-rainfall areas where river erosion is high. Rivers carry sediment from inland, which can deposit in estuaries (brackish areas where rivers meet the sea), later being transported further by waves, tides, and currents. An illustrative example is the sediment delivery to the Gulf of Mexico from river deltas.

Question 24

Why is cliff erosion an important sediment source along coasts?

Answer 24

Cliff erosion provides vital sediment input, particularly in areas of unconsolidated (unstable) cliffs that erode easily. In some regions, coastlines can retreat by up to 10 meters per year, especially during winter storms when erosion is most severe, offering a substantial supply of sediment to the coastal system.

Question 25

In what way does wind influence sediment dynamics along the coast?

Answer 25

Wind is a major energy source that can transport sediment along or up the beach. It moves sand to form dunes and can transport sediment in environments such as deserts or glacial areas where windblown sediments contribute to the coastal system.

Question 26

How do glaciers affect coastal sediment supplies?

Answer 26

In some coastal systems—such as those in Antarctica, Greenland, Alaska, and Patagonia—glaciers deposit sediment directly into the ocean. This process occurs when glaciers calve, meaning ice breaks off and deposits sediment that was stored within the glacier, adding to the coastal sediment budget.

Question 27

Describe how offshore sediment contributes to coastal sediment dynamics.

Answer 27

Offshore sediment becomes part of the coastal zone through erosion by waves, tides, and currents. Offshore bars or sediment sinks are eroded, and the sediment is transported onto the beach. Extreme events like storm surges or tsunamis can also sweep offshore sediment into the coastal area, helping rebuild beaches.

Question 28

What role does longshore drift play in sediment transfer along the coast?

Answer 28

Longshore drift is a vital process where sediment is moved along the beach by the angle at which the swash (incoming wave) approaches the shore. The backwash then carries sediment directly down the beach, creating a continuous cycle of sediment transfer that shifts material from one section of the coastline (output) to another (input).

Question 29

What is a sediment budget and what is its primary purpose?

Answer 29

A sediment budget is a tool that uses data on inputs, outputs, stores, and transfers within a sediment cell to assess the gains and losses of sediment. Its primary purpose is to determine whether a system is in dynamic equilibrium—where sediment inputs equal outputs—and to identify any imbalances caused by natural variations or human actions.

Question 30

What components are used to create a sediment budget?

Answer 30

A sediment budget uses data on the following components: -Inputs: All sediment entering the system (e.g., from rivers, cliff erosion, glaciers, offshore sources). -Outputs: Sediment leaving the system (e.g., via longshore drift, offshore transport). -Stores/Sinks: Areas where sediment is accumulated (e.g., beaches, dunes, estuaries, cliffs). -Transfers/Flows: Processes that move sediment within the system (e.g., wind-blown sand, mass movement, longshore drift, erosion & deposition).

Question 31

How does dynamic equilibrium relate to sediment budgets?

Answer 31

In sediment budgets, dynamic equilibrium refers to the state where the amount of sediment entering (input) equals the amount leaving (output) the system. When a coastal system is in dynamic equilibrium, its sediment budget is balanced. Any disruption in this balance indicates a shift from equilibrium, which can be triggered by natural events or human actions.

Question 32

In what ways can sediment budgets be disrupted?

Answer 32

Sediment budgets can be disrupted by both natural variations—such as storms, fluctuating wave energy, and seasonal changes—and human actions, including coastal development, defences, and pollution. These disruptions can cause sediment inputs and outputs to become imbalanced, altering the system's dynamic equilibrium.

Question 33

Why are sediment budgets important in coastal management planning?

Answer 33

Sediment budgets are crucial in coastal management as they help planners understand the sediment dynamics within a coastal system. By quantifying gains and losses, managers can predict how the coastline may evolve, assess the impact of interventions, and develop strategies that mitigate erosion, enhance sediment deposition, and maintain overall coastal stability.

Question 34

What is the littoral zone?

Answer 34

The littoral zone is the area of land between the coastal features (such as cliffs or dunes) and the offshore area beyond the influence of the waves. It is a dynamic zone that is intermittently covered by the sea.

Question 35

What factors contribute to the constant change within the littoral zone?

Answer 35

The littoral zone is constantly changing due to short-term factors like tides and storm surges, as well as long-term factors such as sea level changes and human interventions.

Question 36

Define the term "shoreline" and explain its significance in coastal geography.

Answer 36

The shoreline, or simply "shore," is the boundary between the sea and the land. It is significant because it marks the line of interaction between marine and terrestrial systems and is a key focus in coastal management and environmental studies.

Question 37

How are the terms "offshore" and "onshore" defined in coastal studies?

Answer 37

Offshore: Refers to the area beyond the influence of the waves, typically not directly affected by immediate coastal processes. Onshore: Refers to the land area that is not covered by the sea but lies very close to it, often experiencing coastal influences such as wind and spray.

Question 38

What is the primary source of energy for all natural systems, and how does it influence the coast?

Answer 38

The sun is the primary source of energy for all natural systems. It influences the coast by driving wind formation through differential heating, which in turn generates waves—the main source of energy at the coast. Additionally, other less common sources such as tectonic activity or underwater landslides can generate tsunami waves.

Question 39

How are waves typically formed at the coast?

Answer 39

Waves form when wind moves across the surface of the water, creating frictional drag that produces small ripples. These ripples lead to a circular orbital motion of water particles. As the seabed shallows towards the coastline, the circular motion becomes more elliptical, causing greater horizontal movement, increased wave height, decreased wavelength and wave velocity, and eventually resulting in the wave breaking and surging up the beach.

Question 40

What role does the seabed depth play in the behavior of waves as they approach the coast?

Answer 40

As the seabed becomes shallower near the coast, water particles’ circular orbits transform into elliptical paths. This enhances the horizontal motion of the waves, increases the wave height, and reduces the wavelength and velocity. Such changes cause water to back up behind the advancing wave, contributing to the wave eventually breaking and surging onto the beach.

Question 41

How does wave energy cause a wave to break near the beach?

Answer 41

As waves approach shallower waters, the orbital motion of water particles becomes elliptical, causing a build-up of water behind the advancing wave. The increased wave height combined with decreasing wavelength and velocity eventually forces the wave to collapse or break, resulting in a surge of water up the beach.

Question 42

What are the main factors affecting the energy of waves generated at the coast?

Answer 42

The 3 main factors affecting wave energy include: Strength of the Wind: Stronger winds, driven by higher pressure differences (caused by differential heating from the sun), generate more powerful waves. Duration of the Wind: A longer duration of wind allows for sustained energy transfer, leading to larger and more energetic waves. Size of the Fetch: The fetch is the distance over which the wind blows uninterrupted over water. A larger fetch means that more energy can build up in the waves before they reach the coast.

Question 43

How does the strength of the wind influence wave energy formation?

Answer 43

The strength of the wind determines the force with which air moves from high to low pressure, creating friction on the water surface. A greater difference in pressure (a stronger wind) imparts more energy into the water, leading to larger, more powerful waves.

Question 44

Explain the significance of the wind’s duration in the formation of waves.

Answer 44

The longer the wind blows, the more energy is transferred continuously to the water surface. This sustained energy input leads to the build-up of wave energy, increasing the height and power of the waves before they approach the coast.

Question 45

What is "fetch" in the context of wave formation, and why is it important?

Answer 45

Fetch is the distance over which the wind blows across open water. It is important because a larger fetch allows the wind to transfer energy over a greater distance, resulting in larger and more powerful waves. The fetch is also influenced by the proximity of land, as nearby land masses can limit the fetch.

Question 46

What is the fundamental difference between constructive and destructive waves regarding their effect on the beach?

Answer 46

Constructive waves deposit material, building up depositional landforms and increasing the size of beaches. Destructive waves remove material through erosion, reducing beach size by eroding depositional landforms.

Question 47

How do the formations of constructive and destructive waves differ?

Answer 47

Constructive waves are formed by weather systems operating in the open ocean, resulting in long, low-energy waves. Destructive waves are typically produced by localized storm events with strong winds near the coast, leading to high, high-energy waves.

Question 48

Describe the differences in wavelength and frequency between constructive and destructive waves.

Answer 48

Constructive waves: Wavelength: Long Frequency: 6-9 waves per minute Destructive waves: Wavelength: Short Frequency: 11-16 waves per minute

Question 49

How do the swash characteristics differ between constructive and destructive waves, and what effect does this have on the beach profile?

Answer 49

Constructive waves: Swash/Backwash: Strong swash with weak backwash. Effect on Beach: Widens and builds up a gently sloped beach through the deposition of sediments. Destructive waves: Swash/Backwash: Weak swash with strong backwash. Effect on Beach: Erodes the beach, contributing to the formation of steeply sloped profiles.

Question 50

In what seasonal and climatic conditions do constructive and destructive waves typically dominate?

Answer 50

Seasonal Variation: Constructive waves often dominate during summer. Destructive waves dominate during winter when storms are more frequent. Climate Change Impact: An increase in storm frequency due to climate change (e.g., in the UK) may lead to more destructive wave conditions. Note: Coastal management can also influence these wave types.

Question 51

How might a storm event affect the classification of wave type in a coastal environment?

Answer 51

Constructive waves can transform into destructive waves if a storm begins. The storm increases wind strength and changes wave dynamics, making waves higher, more frequent, and with a stronger backwash, all of which contribute to a shift toward destructive processes.

Question 52

How do constructive waves influence the beach profile?

Answer 52

Constructive waves deposit sediment on the beach, thereby increasing the amount of material present. This deposition leads to a steeper beach profile over time.

Question 53

What effect does a steeper beach profile have on the type of waves that form?

Answer 53

A steeper beach profile favors the formation of destructive waves. These waves have a strong backwash that erodes the beach more aggressively.

Question 54

Describe the negative feedback loop involving constructive and destructive waves on a beach

Answer 54

The negative feedback loop works as follows: Constructive waves deposit sediment, steepening the beach profile ---> A steeper profile then leads to the formation of destructive waves, which erode the beach and reduce the profile --->With a reduced profile, conditions become more favorable for constructive waves to deposit sediment again, thereby completing the cycle. This loop helps maintain a dynamic equilibrium along the coast, although external factors may disrupt it.

Question 55

How do seasonal variations affect the beach profile in relation to wave types?

Answer 55

In summer, when there are fewer storms and constructive waves dominate, the beach profile tends to be more gentle due to deposition. Conversely, in winter, destructive waves prevail during stormy weather, resulting in a steeper beach profile from increased erosion.

Question 56

Why might the theoretical dynamic equilibrium between constructive and destructive waves not always be achieved in reality?

Answer 56

Although the negative feedback loop should lead to a dynamic equilibrium, external factors—such as variations in wind strength and direction—can disrupt this balance. These impacts may cause shifts in sediment deposition and erosion that prevent the system from reaching or maintaining equilibrium.

Question 57

What role does gravity play in the formation of tides?

Answer 57

Gravity, primarily from the moon and the sun, is the key energy source behind tides. The gravitational pull of these celestial bodies creates variations in water levels (tides) across seas and oceans.

Question 58

What is the tidal range, and where is it often the largest?

Answer 58

The tidal range is the difference in height between high tide and low tide. It is often largest in narrow channels, such as river estuaries, due to the concentration and funneling of tidal energy.

Question 59

What are the 2 types of tide?

Answer 59

Spring tide and Neap tide

Question 60

How do the positions of the sun and the moon affect the tidal range during spring tides?

Answer 60

Spring tides occur when the sun and the moon are aligned. Their gravitational forces combine to pull the water more effectively, producing the highest high tides and the lowest low tides, which results in the largest tidal range.

Question 61

What are neap tides and how do they differ from spring tides?

Answer 61

Neap tides occur when the sun and the moon are perpendicular to each other. Their gravitational forces oppose one another to some extent, resulting in a lower high tide and a higher low tide than during spring tides. This produces the smallest tidal range.

Question 62

In what ways do tides influence coastal landforms and erosion?

Answer 62

Tides play a significant role in coastal processes by affecting erosion and deposition. High and low tides contribute to the shaping of coastal landforms by repeatedly exposing and inundating the shoreline, which can lead to the formation of features such as tidal flats, estuaries, and various erosion patterns along the coast.

Question 63

What are rip currents and how are they formed?

Answer 63

Rip currents are powerful underwater currents that occur close to the shoreline. They form when plunging waves cause a buildup of water at the top of the beach. The backwash, created by resistance from the breaking waves, is forced beneath the surface and flows away from the shore rapidly, often through features like gaps in sandbars.

Question 64

What role do beach features, such as gaps in sandbars, play in the formation of rip currents?

Answer 64

Gaps or weak sections in sandbars allow the concentrated flow of water, which has accumulated from the backwash, to escape more rapidly. This rapid outflow of water is what forms a rip current.

Question 65

What is the difference between rip currents and riptides?

Answer 65

Rip currents occur due to the backwash from breaking waves pushing water away from the beach, typically forming in localized areas along the shore. Riptides, however, are formed when the ocean tide forces water through a narrow area—such as a bay or lagoon. Despite the similar names, their causes and dynamics in coastal environments differ.

Question 66

In what way do rip currents function as an energy source in coastal environments?

Answer 66

Rip currents transport a significant volume of water away from the beach, which can also lead to the removal (or output) of sediment from the beach area. This sediment movement is an important aspect of the coastal sediment budget and influences beach morphology.

Question 67

What characterizes a high-energy coastline?

Answer 67

High-energy coastlines are characterized by powerful, destructive waves—typically found in areas with a large fetch. These intense conditions often lead to rapid erosion, prominent rocky headlands, and a predominance of erosional landforms because the rate of erosion exceeds the rate of deposition.

Question 68

What are some typical features and processes on a high-energy coastline?

Answer 68

On high-energy coastlines, the strong, destructive waves create features such as rock platforms, sea cliffs, and rugged headlands. The constant erosion cuts into the land, so depositional features are less common since there is insufficient sediment supply to counterbalance the erosion.

Question 69

How do low-energy coastlines differ from high-energy coastlines in terms of wave action and sediment deposition?

Answer 69

Low-energy coastlines occur in sheltered areas where the waves are less powerful and constructive waves dominate. This reduced energy allows for increased sediment deposition, resulting in softer, more sandy environments with depositional landforms such as beaches, sand dunes, and spits.

Question 70

Why do low-energy coastlines tend to have depositional landforms?

Answer 70

Since low-energy coastlines receive less wave power, the erosive forces are weaker, allowing the rate of sediment deposition to exceed the rate of erosion. As a result, sediment accumulates to form features like broad, sandy beaches and extensive dune systems.

Question 71

What is wave refraction, and how does it occur?

Answer 71

Wave refraction is the process by which waves bend as they approach the coastline at an angle, particularly around headlands on uneven coastlines. As waves slow down in shallower water, their wavelengths shorten and they turn, focusing energy on headlands while dissipating energy in bays.

Question 72

How does wave refraction affect erosion and deposition along a coastline?

Answer 72

Due to wave refraction, wave energy is concentrated on headlands, leading to increased erosion and the formation of erosional features. In contrast, the dissipated wave energy in bays promotes deposition, forming lower-energy features such as beaches that protect the coastline behind them.

Question 73

Explain how differential rock strengths contribute to the formation of headlands and bays.

Answer 73

Differential rock strengths cause erosion to occur at varying rates along the coast. Resistant rock forms headlands because it erodes more slowly, while unconsolidated rocks and clays erode more easily to form bays. This variation enhances the effects of wave refraction, where headlands experience greater erosive force and bays receive less due to energy dissipation.

Question 74

What are some examples of hard rocks that form headlands and soft rocks that for bays?

Answer 74

Headlands are formed from hard, resistant rocks like chalk and limestone, while bays are formed from softer rocks like clay and sandstone.

Question 75

Describe the negative feedback loop associated with wave refraction on uneven coastlines.

Answer 75

1.Resistant rocks at headlands erode less rapidly, while softer rocks in bays erode quickly, creating a contrast between headlands and bays. 2. Wave refraction focuses energy on headlands, which increases their rate of erosion. 3. As headlands erode further, the process increases erosion within bays as well, once the protective influence of the initial coastal configuration is altered. 4. This cycle would stabilize into dynamic equilibrium if conditions remained constant, but in reality, external factors continually modify the system.

Question 76

How might changing conditions affect the dynamic equilibrium established by wave refraction and coastal erosion?

Answer 76

While the negative feedback loop between headland erosion and bay protection could theoretically lead to a balanced, dynamic equilibrium, external factors—such as variations in wave energy, changes in sea level, or human interventions—can alter sediment supply and rock exposure. Over time, these changes prevent the equilibrium from remaining constant.

Question 77

What is marine erosion (coastal erosion) and how does it function as a collaborative process?

Answer 77

Marine erosion is a collaborative process involving the removal of sediment from a coastline by several types of erosion working together. It is not driven by a single process but by multiple mechanisms working in concert to shape and alter coastal features.

Question 78

What is corrasion, and what factors affect its erosive power?

Answer 78

Corrasion is the marine process in which sand and pebbles are picked up from an offshore sediment sink or temporary store and hurled against coastal cliffs, particularly at high tide. The erosive power of corrasion depends on the shape, size, weight, and quantity of the sediment, as well as the speed of the waves.

Question 79

What do we mean by abrasion in the context of coastal erosion, and how does it differ from corrasion?

Answer 79

Abrasion is the process where sediment is continuously moved along the shoreline, wearing down the coastal surface over time. While corrasion involves hurling sediments against the coastline (akin to throwing stones against an object), abrasion is analogous to rubbing those stones against the surface continuously—the cumulative effect gradually wearing down the material.

Question 80

What does "erosion" mean in a marine context, and why is it described as a collaborative process?

Answer 80

Erosion is the removal of sediment from a coastline. In the marine environment, it does not occur via a single process—instead, several mechanisms work in tandem (such as attrition, corrasion, abrasion, hydraulic action, corrosion, and wave quarrying) to shape the coastline.

Question 81

What is attrition, and what effect does it have on coastal sediments?

Answer 81

Attrition occurs when rocks and pebbles hit against one another as they are moved by waves, causing them to become rounder and eventually smaller. Although it is an erosive process, its primary effect is to modify the size and shape of the sediments rather than directly erode the coastline.

Question 82

Describe hydraulic action and explain how it weakens coastal cliffs.

Answer 82

Hydraulic action happens when waves crash onto rock or cliff faces, forcing air into cracks, joints, and faults. As the wave retreats and the trapped air expands, the pressure widens these cracks, eventually fracturing the rock. Additionally, imploding bubbles (cavitation) create tiny water jets that contribute to further erosion.

Question 83

How does corrosion (solution) contribute to coastal erosion?

Answer 83

Corrosion occurs when mildly acidic seawater dissolves alkaline rocks like limestone. This process is akin to carbonation weathering and represents a potential link between the carbon cycle, global warming, and coastal erosion. There is ongoing debate about whether increases in rainfall and ocean acidity will significantly accelerate erosion.

Question 84

What is wave quarrying, and how does it differ from hydraulic action?

Answer 84

Wave quarrying is when the force of breaking waves—which can exert pressures up to 30 tonnes per m²—directly pulls away rocks or small weathered fragments from a cliff face. Though similar to hydraulic action, wave quarrying operates under much higher pressures, essentially “hammering” the rock and making it more vulnerable to further erosion from hydraulic action and abrasion.