Coasts 🏖

• Suspension is when fine material such as clay and sediment are carried by the sea.
• Solution is when dissolved minerals are carried by the sea.
• Traction is when large boulders and pebbles are rolled along the sea bed.
• Saltation is when small stones, pebbles and silt bounce along the sea bed.
• Hydraulic action is when the power of the waves hitting up against the cliff cause air to get trapped in cracks in the rock which causes it to break.
• Abrasion is when destructive waves throw material at the cliffs between the high and low watermarks. The rocks then scratch and scrape the cliff face.
• Solution is when certain types of cliffs erode as a result of weak acids in the sea.
• Mass movement is when rocks loosened by weathering move down slop under the influence of gravity.
• Rock falls (sliding) is when large and small fragments of rocks are weathered until they seperate and fall from the cliff.
• Slumping is when large areas of land move down a slope.
• Soil creep is the slowest type of mass movement. It is when gravity pulls the water contained in soil downwards which pulls the soil with it.
• Weathering is when rocks are broken down by either mechanical, chemical or biological processes caused by the weather. (Like freeze-thaw)
• Beaches are deposits of sand and shingle at the coast. They are formed by constructive waves and deposition.
• Headlands are more resistant parts of rock that are harder to erode.
• Bays are areas of softer rocks caused by deposition.
• Constuctive waves are the waves which build up the beaches, they have a large swash and little backwash.
• Destructive waves are waves which destroy the beaches, they have a large backwash and weaker swash.
• Cracks in the headland are widened due to hydraulic action and abrasion. As waves continue to grind at the crack it opens up and forms a cave. The cave becomes larger and breaks through the headland to form an arch. The base of the arch continually becomes wider through further erosion, until its roof becomes too heavy and collapses into the sea. This leaves a stack. Then it is undercut and becomes a stump.
• Hard engineering means using artificial structures such as sea walls to control natural processes.
• Soft engineering is less intrusive more environmentally friendly methods that work with natural processes to protect the coast.
• Sea wall:

  Positives - effective and often used as a walk way.

  Negatives - can look unatural, very expensive and has high matinence costs.
• Groynes:

  Positives - wider beach and is cheaper

  Negatives - unatural, unattractive, will rot, it shifts the issue of erosion and doesnt stop it.
• Gabions:

  Positives - cheap to produce and will eventually merge into the landscape.

  Negatives - looks unattractive for a while and cages only last 5-10 years before they rust.
• Rock armour:

  Positives - relatively cheap and easy to maintain.

  Negatives - too expensive to transport, obstructive and doesn't fit in with the local geography.
• Beach nourishment:

  Positives - relatively cheap, blends in and also increases tourism.

  Negatives - needs constant maintenance.
• Dune regeneration:

  Positives - maintains a natural coastal environment and is cheap.

  Negatives - can be damaged easily by storms and people will complain about being prohibited entry.
• Dune fencing:

  Positives - minimal impact on natural systems.

  Negatives - regular maintenance needed and it can be unsightly if fences break.
• Managed retreat:

  Positives - cheap, salt marshes can be created and it allows for natural processes to take place.

  Negatives - people homes may be left to fall into the cliff and land owners need to be compensated for their loss.
• Flamborough head is Made from chalk. Erosion from the sea here is slow and it creates cliffs. It also has stacks and wave cut platforms.
• Mappleton has 50 properties. It has had intense erosion at a rate of 2m a year which has resulted in the access road being 50m from the cliff edge.
• Mappletons groynes have pushed their issue of erosion to Cowden. Erosion has went from 1m a year to 20m a year and they have had to use managed retreat as no one is paying to save the farm.
• Withernsea is a relatively large settlement which is economically valuble ans has high tourism levels. They have put in a curved sea wall, rock armour and groynes.
• Easington gas terminal has erosion at a rate of 1.8m a year. They have put in a kilometer long stretch of rock armour using over 130,000 tons of rock.
• Spurn point is a sand and shingle spit 5.5km long across the mouth of the humbler river.
• Longshore drift is the movement of sediments along a coast by waves that approach at an angle to the shore but then the swash recedes directly away from it.
• Sand dunes are large piles of sand that form at the back of sandy beaches.
• Cliffs are shaped through erosion and weathering Soft rock erodes quickly and forms gentle sloping cliffs, whereas hard rock is more resistant and forms steep cliffs. A wave-cut platform is a wide gently-sloping rocky surface found at the foot of a cliff.
• A spit is an extended stretch of sand or shingle jutting out into the sea from the land. Spits occur when there is a change in the shape of the landscape or there is a river mouth or estuary.
• Bars are linear ridges of sand/shingle extending across a bay and are connected to land on both sides. It traps a body of seawater behind it, forming a lagoon.
• A tombolo is one or more sandbars or spits that connect an island to the mainland.