Keywords Flashcards
Abrasion
The wearing away of cliffs by sediment flung by breaking waves.
Arch
A wave eroded passage through a small headland. This begins as a cave formed in the headland, which is gradually widened and deepened until it cuts through.
Attrition
Erosion caused when rocks and boulders transported by waves bump into each other and break up into smaller pieces
Bar
Where a spit grows across a bay, a bay bar can eventually enclose the bay to create a lagoon. Bars can also form offshore due to the action of breaking waves.
Beach
The zone of deposited material that extends from the low water line to the limit of storm waves. The beach or shore can be divided in the foreshore and the backshore.
Beach nourishment
The addition of new material to a beach artificially, through the dumping of large amounts of sand or shingle.
Beach reprofilling
Chasing the profile or shape of the beach. It usually refers to the direct transfer of material from the lower to the upper beach or, occasionally, the transfer of sand down the dune face from crest to toe
Cave
A large hole in the cliff caused by waves fording their way into cracks in the cliff face
Chemical Weathering
The decomposition (or rotting) of rock caused by a chemical change within that rock; sea water can cause chemical weathering of cliffs
Cliff
A steep rock face formed by weathering and erosion along the coastline
Deposition
Occurs when material being transported by the sea is dropped due to the sea losing energy.
Dune regeneration
Action taken to build up dunes and increase vegetation to strengthen the dunes and prevent excessive coastal retreat. This includes the replanting of marram grass to stabilise the dunes, as well as planting trees and providing boardwalks.
Erosion
The wearing away and removal of material by a moving force, such as a breaking wave.
Gabion
Steel wire mesh filled with boulders used in coastal defences
Groyne
A wooden barrier built out into the sea to stop the longshore drift of sand and shingle, and so cause the beach to grow. It is used to build beaches to protect against diff erosion and provide an important tourist amenity, However, by trapping sediment it deprives another area, down-drift, of new beach material.
Hard engineering
The use of concrete and large artificial structures by civil engineers to defend land against natural erosion processes.
Headlands and Bays
A rocky coastal promontery made of rock that is resistant to erosion; headlands lie between bays of less resistant rock where the land has been eroded back by the sea.
Hydraulic Action
The process by which breaking waves compress pockets of air in cracks in a cliff. The pressure may cause the crack to widen, breaking off rock.
Longshore Drift
The zigzag movement of sediment along a shore caused by waves going up the beach at an oblique angle(wash) and returning at right angles(backwash). This results in the gradual movement of beach materials along the coast
Managed retreat
Allowing cliff erosion to occur as nature taking its course: erosion in some areas, deposition in others.
Benefits include less money spent and the creation of natural environments. It may involve setting back realigning the shoreline and allowing the sea to flood areas that were previously protected by embankments and seawalls
Mass movement
he downhill movement of weathered material under the force of gravity. The speed can vary considerably
Mechanical Weathering
Weathering processes that cause physical disintegration or break up of exposed rock without any change in the chemical composition of the rock, for instance freeze thaw.
Rock armour
Large boulders dumped on the beach as part of the coastal defences.
Sand Dune
Coastal sand hill above the high tide mark, shaped by wind action, covered with grasses and shrubs.
Sea Wall
A concrete wall which aims to prevent erosion of the coast by providing a barrier which reflects wave energy.
Slumping
Rapid mass movement which involves a whole segment of the cliff moving down-slope along a saturated shear-plane or line of weakness.
Soft Engineering
Managing erosion by working with natural processes to help restore beaches and coastal ecosystems.
Spit
A depositional landform formed when a finger of sediment extends from the shore out to sea, often at a river mouth. It usually has a curved end because of opposing winds and currents
Stack
An isolated pillar of rock left when the top of an arch has collapsed. Over time further erosion reduces the stack to a smaller, lower stump
Transportation
The movement of eroded material.
Wave cut platform
A rocky, level shelf at or around sea level representing the base of old, retreated cliffs
Waves
Ripples in the sea caused by the transfer of energy from the wind blowing over the surface of the sea. The largest waves are formed when winds are very strong, blow for lengthy periods and cross large expanses of water.
