coasts

• Coastline

  The outline of the edge of the land on a map.
• Shore

  The area between the lowest tide level and the highest point reached by storm waves is known as the shore,
• Bay

  An approximately semi-circular shape of sea extending into the land between two headlands.
• High/Low water mark

  The sea rise to a high level and falls to a low level normally twice a day exposing more/less of the beach.
• Fetch

  The length of sea over which the wind blows.
• Wave crest

  The highest point of the wave when it rises (its peak)
• Wave trough

  The lowest point between two wave crests.
• Coral reef

  a ridge of rock in the sea formed by the growth and deposit of coral
• (Fringing/barrier/atoll)

  Corals are tiny marine animals called polyps that forms reefs when they live in colonies in their millions. Their skeletons are calcareous cup like structures which when join form a stony mass.
• Swash

  When water rushes up the beach.
• Backwash

  When water drains back down the beach.
• Headland

  Projects out into the sea and is usually longer than its breadth. Its sides are cliffs.
• Destructive waves

  Have a weak swash and a strong backwash and destroy the beach through erosion.
• Constructive waves

  Have a strong swash and a weak backwash and build up the beach through deposition.
• Erosion (HAAS)

  See rivers glossary - Hydraulic action/Attrition/Abrasion/ Corrosion (solution)
• Shingle

  Rounded beach material of intermediate size between boulders and sand.
• Transportation (SSST)

  See rivers glossary - Solution/Suspension/Saltation/Traction
• Longshore drift

  The movement of sediment along a beach.
• Hard Engineering

  Methods to reduce/prevent erosion that involve permanent changes to the coastline using expensive man-made materials that are often visually polluting but effective. E.g. Groynes / Gabions / Sea Wall / Revetments / Rip Rap / Breakwater
• Soft Engineering

  Methods to reduce erosion that use natural materials and that do not significantly change the look of the coastline. Often less expensive and more sustainable but require more maintenance e.g. Beach nourishment / Cliff regrading / Managed retreat / Dune stabilisation
• Mangrove Swamps

  These are found in tropical regions in low energy environments where mud settles and salt tolerant plants survive.
• Oblique prevailing wind

  The direction of the wind that occurs most frequently and hits the coastline at an angle.
• Wave-cut notch/platform

  An indentation at the base of a cliff at high-tide level where wave attack has undercut the rock. The cliff above the notch collapses and the cliff line retreats. This process is repeated leaving a rock platform where the cliff once stood.
• Discordant coastline

  Where different types of rock lie at right angles to the sea and suffer differential erosion.
• Concordant coastline

  Where different types of rock lie perpendicular to the sea so erosion is more consistent.
• Cave/Arch/Stack/Stump

  Formed due to the erosion at a headland, started at lines of weakness in the rock.
• Wave refraction

  As oblique waves enter shallow water, they tend to turn so that their crests are parallel to the coast.
• Beach

  Composed of sand and/or shingle they are found in bays caused by deposition.
• Spit

  When longshore drift happens and the coastline changes direction deposition will continues in open water eventually the material rises above the water creating a beach, curved at one end.
• Bar

  If a spit grows out across a bay it can sometimes reach the whole way across.
• Lagoon

  The area of water enclosed by the bar.
• Salt Marsh

  If a bar forms across the mouth of a river the lagoon will fill up with sediment forming a marsh. This can also happen behind a spit as it is a low energy environment where mud can settle.
• Tombolo

  Is a spit connecting an island to the mainland.
• Sand dunes

  Ridges of sand which form at the back of beaches and on spits. They have a staged development from (Embryo/Fore/Mobile/Semi-fixed/Fixed)
• Soft engineering - examples

  Managed retreat, supplying more sand to the beach
• long shore drift

  The movement of water and sediment down a beach caused by waves coming in to shore at an angle
• Diagram of long shore drift

  
• What angle does prevailing wind come from

  Oblique angle
• Example of an erosional landform


  Stacks, arches, caves, headlands, bays, cliffs, onshore platforms
• spit

  Deposition of sand sticking out into the ocean caused by longshore drift