Coasts

• Lithology

  The general physical characteristics of rocks
• Morphology

  The geological structure, shape or form of a feature
• Submerging coast

  Stretch of coastline inundated by the sea due to ecstatic or isostatic changes
• Emergent coast

  Stretch of coastline that has been exposed by falling sea levels or isostatic uplift
• Concordant coast

  Rock structure run parallel to the coast. This forms coves
• Discordant coast 


  Rock structure run perpendicular to the coast creating bands of alternate rock types. This forms headlands and bays
• Offshore

  The area of deeper water beyond the point at which waves begin to break. Friction between the waves and the sea bed may cause some distortion of the wave shape.
• Nearshore

  The area of shallow water beyond the low tide mark, within which friction between the seabed and waves distorts the wave sufficiently to cause it to break. (breaker zone) There may be a breakpoint bar between the offshore and nearshore zones.
• Foreshore

  The area between the high tide and the low tide mark.
• Backshore

  The area above the high tide mark, affected by wave action only during major storm events.
• Long term criteria to categorise coasts

  Geology

  Sea level change
• How can sea level change be used to classify coasts

  Can be used to classify them into submerging or emergent.

  This can be caused by tectonic processes which lift sections of land up or climate change which can cause sea level to rise or fall
• Short term criteria used to classify coasts

  Energy inputs

  Sediment inputs
• How can energy inputs be used to classify coasts

  Coasts receives energy inputs from waves, tides and currents. This can be used to classify coasts into high energy and low energy
• How can sediment inputs be used to classify coasts

  Coasts receive sediment inputs from waves, wind, tides, currents, mass movement and tectonic processes. Sediment is added to a coastline through deposition and removed by erosion.

  When deposition is more than erosion it is an outbuilding coastline

  When erosion is more than deposition it is an eroding coastline
• Outbuilding coastline

  Where deposition more than erosion there is a net gain of sediment and the coastline advances making it an outbuilding coastline.
• Eroding coastline

  Where erosion more than deposition there is a net loss of sediment and the coastline retreats making it an eroding coastline.
• Estuary


  An estuary is a partially enclosed area of water on the coast where saltwater from the sea mixes with fresh water from rivers and streams
• Valentin's classification

  Classifies coasts into emerging, submerging, eroding and outbuilding

  
• What type of coasts are high energy coastlines

  Rocky coasts
• Waves at high energy coasts

  More powerful destructive waves
• Processes at rocky coasts

  Erosion exceeds deposition

  Mass movement

  Weathering
• Landforms at high energy coasts

  Wave cut platform and wave cut notch

  Caves, arch, stacks and stumps
• Example of high energy coast

  Cornwall

  North Western Scotland
• What type of coastlines are low energy coasts

  Coastal plain landscapes such as sandy and estuarine coasts
• Processes at low energy coasts

  Deposition
• Landforms at low energy coasts

  Beaches

  Spits

  Bars

  Salt marshes

  Sand dunes

  Mudflats
• Examples of low energy coasts

  Cleethorpes
• What main 3 elements does geological structure relate to

  Strata

  Deformation

  Faults
• Deformation

  The degree of tilting and folding
• Faulting

  Fractures causing rocks to be displaced from their original positions
• Strata

  Different layers of rock
• Joint

  A fracture in a rock in which no movement of displacement of the rock is observable
• Dip

  The dip of a bedding plane is the angle which it makes with a horizontal plane
• Dalmatian coastline

  A dalmatian coastline is composed of long, narrow islands running parallel to the coastline and separated by narrow sea channels.
• Haff coastline

  Haff coasts are long sediment ridges topped by sand dunes that run parallel to the coast
• How are sand dunes formed

  Newly formed sand dunes closest to the sea collect sand to become larger then plants such as marram grass and sea rockets are able to colonise the stable dunes to hold the sand together
• Igneous rock

  Very slow erosional rate as its resistant eg granite
• Metamorphic rock

  Resistant to erosion, folded and fractured so are sometimes vulnerable
• Sedimentary rock

  Weak and easily eroded eg sandstone and limestone