Coasts Flashcards
Landscape
An extensive area of land regarded as being visually and physically distinct
Abrasion
The wearing away of cliffs by sediment flung from breaking waves
Arch
A wave-eroded passage through a small headland. This begins as a cave formed in a 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 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 Reprofiling
Changing 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 crest to toe
Cave
A large hole in a cliff caused by waves forcing their way into cracks in the cliff face
Chemical Weathering
The decomposition of rock caused by a chemical change within that rock; sea water can cause chemical weathering of cliffs
Cliff
A steep high 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 re-planting 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
Hydraulic Power
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 (LSD :D)
The zigzag movement of sediment along a shore caused by waves going up the beach at an oblique angle (swash) 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 it’s course; erosion in some areas, deposition in others. Benefits include less money spent and the creation of natural environments. It may involve setting back or realigning the shoreline and allowing the sea to flood areas that were previously protected by embankments and seawalls
Mass Movement
The 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 that aims to prevent erosion of the coast by providing a barrier which reflects wave energy
Sliding
Occurs after periods of heavy rain when loose surface material becomes saturated and the extra weight causes the material to become unstable and move rapidly downhill, sometimes in an almost fluid state
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 the 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
