Subaerial processes (weathering and mass movement) work together to influence rates of coastal recession. Weathering weakens rocks above high tide mark, making mass movement easier by reducing the internal cohesion of the rock. Repeated mass movement leads to rapid coastal recession.

What affects the rate of coastal recession?

The biggest factor affecting coastal erosion is the strength of the waves breaking along the coastline. A wave’s strength is controlled by its fetch and the wind speed. … Weathering also plays a role in the rate of erosion by creating weaknesses in rocks that are exploited by the processes of erosion.

What is the influence of subaerial processes on coastal landforms?

Sub-aerial processes include weathering and mass movement. These processes operate on the cliff face to weaken it and provide material for coastal erosion.

What is the role of subaerial weathering in coastal environments?

The role of weathering is to weaken cliffs. This weakening speeds up the rates of erosion. Another sub-aerial process is mass movement. A mass movement refers to the movement of material downslope under the influence of gravity.

How does geological structure affect coastal recession?

Geology The geological structure of coasts and the types of rock found there influence the erosion landscapes formed. … Four types of erosion: Hydraulic action—the weight and impact of water against the coastline and cliffs erodes them. Abrasion—breaking waves throw sand and pebbles against the coast during storms.

Why do rates of coastal recession vary?

Rates of recession are not constant and are influenced by different factors, both short- and longer-term (wind direction/fetch, tides, seasons, weather systems and occurrence of storms.

What factors influence coastal processes?

• The rock type/geology (see map below). …
• The fetch of the wave and the strength of the wind. …
• The angle of the slope – steep slopes erode more violently and frequently.
• Weather conditions – freezing temperatures and heavy rain increase weathering and the rate of erosion.

What are Subaerial processes geography?

Sub-aerial process are land-based processes which alter the shape of the coastline. These are a combination of weathering and mass movement.

What is the difference between marine and subaerial processes?

Sub – aerial processes can include weathering processes such as chemical weathering, mechanical and biological weathering. Mass movement is also a form of sub – aerial processes. Marine Processes include erosion like hydraulic action and deposition in forms such as longshore drift.

How do coastal processes result in coastal erosion submersion and saltwater intrusion?

Coastal processes are unavoidable occurrences driven by nature and amplified by human action. They cause damage to the shorelines through coastal erosion, submersion, and saltwater intrusion. … Breakwaters are offshore structures that protect coasts from parallel waves and in turn, prevent erosion and submersion.

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How does mass movement cause coastal recession?

Damp soil moves very slowly down the slope as the weight of water pushes it forwards. Rain splash may release soil grains that fall further downslope. Landslides arise when rocks and unconsolidated material on the cliff face are saturated with water (rain or wave-splash). Eventually the material slips down the slope.

What are the two process interacting in a highly dynamic natural system of coastlines?

Coastlines are highly dynamic natural systems that interact with terrestrial, marine and atmospheric processes and undergo continuous change in response to these processes.

How do coastal processes result in submersion?

Submersion is the sustainable cyclic portion of coastal erosion where coastal sediments move from the visible portion of a beach to the submerged nearshore region, and later return to the original visible portion of the beach. The recovery portion of the sustainable cycle of sediment behaviour is (accretion).

How does geological structure influence coastal morphology?

Geological structure is responsible for the formation of concordant and discordant coasts. … Geological structure (jointing, dip, faulting, folding) is an important influence on coastal morphology and erosion rates, and also on the formation of cliff profiles and the occurrence of micro-features, e.g. caves.

How geological structure can influence the erosion of a coastal headland?

When a stretch of coastline is formed from different types of rock, headlands and bays can form. Bands of soft rock such as clay and sand are weaker therefore they can be eroded quickly. This process forms bays. … When the softer rock is eroded inwards, the hard rock sticks out into the sea, forming a headland .

What is coastal recession geography?

Coastal erosion is the wearing away and breaking up of rock along the coast. Destructive waves erode the coastline in a number of ways: Hydraulic action: Air may become trapped in joints and cracks on a cliff face. When a wave breaks, the trapped air is compressed which weakens the cliff and causes erosion.

What are the factors that affect the rate and nature of coastal transportation?

Various external factors greatly influence coastal transportation such as weather patterns, climate, and other hydrometeorological events. For example, as weather patterns become more intense, materials and sediments can be transported to farther distances.

What are coastal processes?

coastal processes driven by winds, waves and currents began to sculpt the edges of the coastline. … Other processes which influence the coastal environment include longshore drift, winds and wave erosion. These coastal processes can produce and expose some interesting features.

Why are coastal processes important?

Coastal processes shape the physical environment, providing habitat such as turtle or seabird nesting beaches, reefs, and mangrove forests or seagrass beds.

Why does deposition occur along the coast?

When the sea loses energy, it drops the sand, rock particles and pebbles it has been carrying. This is called deposition. Deposition happens when the swash is stronger than the backwash and is associated with constructive waves.

What factors affect the rate of erosion and deposition?

Factors that affect the rate of erosion include weather, climate, shape of the land, and type of rock. The presence of plants and the way humans use the land affect the rate of erosion.

Why are coastal landscapes different and what processes caused these differences?

Rocky coasts (high and low relief) result from resistant geology (to the erosive forces of sea, rain and wind), often in a high energy environment, whereas coastal plain landscapes (sandy and estuarine coasts) are found near areas of low relief and result from supply of sediment from different terrestrial and offshore …

What is marine and coastal processes?

The coastal zone is that part of the land surface influenced by marine processes. The atmospheric processes include temperature, precipitation, and winds, while the major marine processes are waves and tides, together with water temperature and salinity. …

What is the difference between hydraulic action and wave quarrying?

Hydraulic action – this process occurs where the power of the waves hits the cliff face directly and loosens the interior of joints and bedding planes. … Wave quarrying – when high energy, tall waves hit the cliff face they have the power to enlarge joints and remove large chunks of rock in one go through vibration.

How is a discordant coastline formed?

A discordant coastline occurs where bands of different rock type run perpendicular to the coast. The differing resistance to erosion leads to the formation of headlands and bays. … The Portland limestone is resistant to erosion; then to the north there is a bay at Swanage where the rock type is a softer greensand.

What is the difference between coastal erosion and coastal submersion?

While erosion is the process of removing sediment, submersion is when the sediment is submerged under water and eventually replaced back to its original location.

What can you do to lessen the effects of marine and coastal processes?

1. Always pack your reusable water bottle. …
2. Ditch single-use cups, straws and utensils. …
3. Bring that reusable mindset into the grocery store. …
4. Consider the parts of your environmental impact that you can’t see.

What is the cause of saltwater intrusion?

Generally, saltwater intrusion into coastal aquifers is caused by two mechanisms: Lateral encroachment from the ocean due to excessive water withdrawals from coastal aquifers, or. Upward movement from deeper saline zones due to upconing near coastal discharge/pumping wells.

What is the link between weathering and mass movement?

The broken rock fragments (as a result of weathering) move down the slope through mass movements . These can be rapid, such as landslides or slow as with soil creep: Landslides are occasional, rapid movements of a mass of earth or rock sliding along a steep slope.

How does mass movement affect the coastline?

Mass movement – Once weakened by weathering mass movement can then deliver this material to beaches and the sea to be eroded. Some mass movement processes occur slowly, such as soil creep and solifluction, but some are very rapid such as rock falls.

What affects the rate of mass movement?

Such factors include: weathering or erosional debris cover on slopes, which is usually liable to mass movement; the character and structure of rocks, such as resistant permeable beds prone to sliding because of underlying impermeable rocks; the removal of the vegetation cover, which increases the slope’s susceptibility …