S-Cool Revision Summary

S-Cool Revision Summary

Backshore This area is not usually encroached upon by waves - unless storm conditions arise.
Foreshore and nearshore The foreshore is located closest to the backshore and it is here, due to the breaking of waves that sediment transport may take place.
Offshore There is limited direct sediment movement here as tidal currents are more important than wave action.
Constructive waves These are depositional waves as they lead to sediment build up, and are most common where a large fetch exists.
Destructive waves These act as agents of erosion, because backwash is greater than swash.
Wave fetch The distance of open water over which a wave has passed.
Wave crest Highest point of a wave.
Wave trough Lowest point of a wave.
Wave height Distance between trough and crest.
Wave length Distance between one crest/trough and the next.
Swash Water movement up a beach.
Backwash Water movement down a beach.
Abrasion/corrasion Occurs when material, such as sand, shingle, pebbles and boulders is hurled against cliffs as waves hit them, wearing the cliff away.
Hydraulic pressure When water is thrown against rock, a parcel of air can become trapped/compressed in a joint or crack. The increase in pressure leads to a weakening/cracking of the rock.
Corrosion/solution Seawater contains carbonic acid, which is capable of dissolving limestone. The evaporation of salts in seawater produces crystals and their formation can lead to the disintegration of rocks.

Sub-aerial

Coastal erosional processes that are not linked to the action of the sea. Erosion occurs via rain, weathering by wind and frost. Its impact is often seen in soil creep, slumping and landslides.
Human activity Much building and recreation occurs at the coast, and this increases pressure on cliff "top"s, making them more liable to erosion and subsidence.
Hard rock cliffs Examples include granite and basalt cliffs. They exhibit a slow rate of erosion and tend to be stable.
Soft rock cliffs Examples include cliffs comprised of glacial till and clay. These cliffs often erode rapidly.
Headlands and bays Hard rock, which resists erosion followed by soft rock that has been eroded to form a bay.
Wave cut platforms These are gently sloping features, often found extending from the base of a cliff.
Caves, arches, stacks, blowholes Secondary features occurring during cliff formation. Originate due to lines of weakness (joints or faults) being attacked and made larger by marine erosion.
Arch When two caves formed on either side of a headland join together.
Stacks Collapsed arches.
Stumps Stacks that have been eroded and lost height.
Clastic sediment Comes from weathering of rock and varies from very small clay particles to sand/pebbles/boulders.
Biogenic sediment Skeletons and sediments of marine organisms.
Non-cohesive sediment Larger particles (for example, sand) moved grain by grain.
Cohesive sediment Very small clay and mud particles that bond together.
Longshore drift Process whereby material is moved along a stretch of coastline. Material is transported in a zig-zag fashion.
Beaches Commonest form of coastal deposition - occurs as a result of sediment being deposited, that may have come from rivers, and cliff erosion.
Spits Narrow, long stretches of sand/shingle that extend out to sea, or partway across a river estuary.
Sandy spits Form as a result of dominant constructive swell waves.
Shingle spits Form as a result of dominant destructive waves.
Tombolos Where a spit or bar connects the mainland to an island.
Barrier beaches and islands A number of sandy beaches that are totally separate to the main land, but run parallel to it.
Cuspate forelands Triangular beaches formed by longshore drift operating on a coastline from two different directions.
Sand dunes Not strictly a feature resulting directly from marine action, but the blowing of sand from a beach inland.
Embryo dune The first part of the dune to develop.
Yellow dune Colour is due to a lack of humus, but with distance inland they become increasingly grey due to greater amounts of humus.
Fixed grey dunes Limited growth due to distance from beach.
Dune slacks Depressions between dune ridges, which will be damp in summer and water-filled in winter.
Blow outs Large ‘holes’ that appear in the dunes. Often evidence of over use by humans.
Mud flat A level area of fine silt along a shore as in a sheltered estuary. Alternatively covered and uncovered by the tide, or covered by shallow water.