coastal landscapes

• cliffs and wave cut platforms

  Cliffs are formed when the sea erodes the land. They often retreat due to erosion and weathering. Weathering and wave erosion can cause a notch to form at the high water mark and develop into a cave. The rock above the cave becomes unstable and collapses. Wave-cut platforms are flat surfaces left behind after the cliff is eroded.
• Headlands and bays


  A headland is formed when there are alternating bands of soft rock and hard rock. The softer rock will erode quicker leading the hard rock as it is more resistant to erosion. The erosion of the soft rock will form a bay.
• Caves, arches and stacks

  The joints on a cliff or headland gets eroded away and weakens the joint to form caves. This erosion continues until it has reached the other side of the headland and this forms an arch. When the top of the arch is too heavy, it will collapse and fall creating a stack.
• Beaches


  They are formed when constructive waves are deposit sediment. This creates a store of sediment. Shingle rocky beaches are more steep and narrow. This is because they are made up from, larger particle which pile up at a steep angle. Sand beaches are formed from smaller particles so they hare more gentle sloping and wider.
• Beach features

  • Berms are ridges of sand and pebbles found at high tide marks
• Beach features

  • berms which are ridges on the sand that are found at the high tide mark
  • Runnels that are groves in the sand running parallel to the shore formed by the backwash
  • Cusps that are crescent shaped indentations that form on the beaches of mixed sand and shingles
• Spits


  Formed when there is a change in direction. Longshore drift continues to deposit material across the river mouth and leaving a bank of sand and shingles sticking out into the sea. A straight spit the grows out roughly parallel to the coastline is a simple spit. When there are changes to the dominant winds the wave direction may lead to a spit having a recurved end. Overtime there may be many recurved end spits and forms a compound spit. The area behind the spit is sheltered from the waves and develops into a mudflat or a salt marsh
• Offshore bars and tombolo

  Bars are formed when 2 spits join together across a bay or mouth. This forms an area of still water known as a lagoon. Bars can also form offshore when the sediment is moving towards the coast, typically as sea level rises. These bars remain submerged. A tombolo is when a bar s connected to an island
• Barrier islands

  • Long narrow islands of sand that run parallel to the shore and are detached from it.
  • Formed when there is a good supply of sediment, gentle slope and a small tidal range
  • formed after the last ice age when ice melted and cause a rapid sea level rise.
  • The sea flooded the land behind the beaches and transported the sand offshore to form barrier islands.
  • another theory is that the barrier islands originated as bars however some parts got eroded and the abr became detached
• Sand dunes

  • Formed when the sand is deposited by longshore drift by the wind
  • The sand is trapped and then the plants colonise the embryo dune to stabilise the sand which enlarges more sand to be deposited
  • Over time the oldest dunes migrate inland’s to form mature dunes up to 10 metres high
• Estuarine mudflat and salt marshes.

  • mudflats and salt marshes are sheltered, low energy areas and typically located behind a spit
  • As silt and mud is being deposited the mudflat develops
  • the mudflat are being colonised by vegetation that can handle the high salt levels and long periods of submergence
  • The plants troops more mod and silt and they gradually build up to create a area of salt marsh that remains exposed for longer and longer between tides
  • erosion by tidal currents forms channels on the surface of the mudflats and salt marshes which may be permanently flooded or dry
• Eustatic rise


  Eustatic sea level rise is caused by the volume of water changing or change of the basin shape. It is a global change and climate change can cause this:

  • Increase in temperatures causing meting in ice sheets so increases the sea levels
  • Decrease in temperature will cause more ice to form so decreasing sea levels

  Tectonic plate movement can alter the shape of the earths crust such as sea floor spreading so decreasing the sea levels
• Isostatic rise

  This is caused by the change of land relative to the sea. A downward movement of land will cause sea level to rise but an upward will cause a decrease in sea level. The main causes are:

  • Uplift or depression of the earths crust due to the accumulation or melting of ice sheets. Slow uplift can occur when the glaciers have melted and the weight has been removed. Accumulation of sediment occurring at a mouth can cause a depression.
  • Subsidence of land due to shrinkage after abstraction of ground water
  • Tectonic processes such as subduction beneath another plate
• Sea level in the past 10,000 years 


  The sea level varys due to the tidal cycle. Onshore winds and low atmospheric pressure systems can case the sea level to rise temporarily. Globally the sea level has changed lots.

  • The last glacial period saw a decrease in sea level as the ice is stored in sheets. 130m decrease
  • Temperatures started to rise so the ice started to melt and sea levels rose quickly
  • Over the last 4000 years the sea level has fluctuated bit since 1930 it haas started to rise again
• Sea level rise due to climate change

  Global temperatures have started to rise rapidly due to human actions. Increase in temperatures has caused an increase in sea levels due to thermal expansion and ice melting. Global levels has seen a rise of 2mm each year . Could see a 8-16mm increase a year by 2100
• Impacts of climate change sea level rise


  • More powerful storms becoming more frequent as the sea surface temperatures gets hotter
  • More frequent and severe coastal flooding of low lying areas
  • Submergence of low lying islands and are at risk of disappearing
  • Change in the coastline as islands are being created or lost due to submergence
  • Contamination of water sources and farmland causing harder to farm and damaging ecosystems
  • Increase in coastal erosion and some places are at risk of collapsing
• Kings point in New york

  • Flooded around 160 times from 2005-2014
• Maldives


  • At risk of being submerged
• Bangladesh


  • Losing 8000km if sea level rises by 0.3m
• Holderness, UK


  • At risk of collapsing due to coastal erosion