2B.1
The littoral zone (costal zone)
constantly changing due to dynamic interaction between processes operating in the sea, ocean, and on land.
stretches out to sea and onto the shore
The littoral zone is one of dynamic equilibrium, due to the wide range of natural processes interacting with it.
back-shore and the foreshore are where the greatest level of human activity occurs, and physical processes mostly occur.
factors that may influence this zone
Short term factors: individual waves, daily tides, and seasonal storms.
Long term factors: sea level change and climate change.
factors that cause coasts to vary
Geomorphic
Anthropogenic
infrastructure
people
rocktype
Energy of the coast
vegetation
prevailing winds
direction of longshore drift
Processes
inputs
out puts
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Marine (waves, tides, storm surges)
Atmospheric (weather/climate, climate change, solar energy)
Land (rock type and structure, tectonic activity)
People (human activity, coastal management)
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Weathering (wearing away of material) Mechanical and physical weathering
Mass movement (movement of surface material)
Erosion (wearing away of material)
Transport (movement of sediment)
Deposition (dropping off of sediment)
Erosional landforms (arch, stack, stump, headland, bay)
Depositional landforms (splits, tombolos, beaches)
Different types of coasts (rocky shores, sandy beaches, coastal wetlands, coral reefs)
Dynamic equilibrium
(A state of balance between continuing processes.)
factors which may affect t this
Waves
Dredging
Tides
Climate change
Valentine’s Classification of coasts
Sections of coast can be classified into different types using a variety of criteria, such as geology, sea-level rise and fall, and land-level rise and fall, which cause long-term changes, and erosion and deposition, which cause short-term changes.
Isostatic Land Change
change is a change in local land level.
Rises in local land level causes a fall in local sea level.
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This may be due to:
Post-glacial adjustment
Accretion
Sink regions in the sediment cell are experiencing net deposition, land is built up, leading to a fall in sea level.
Eustatic Land Change
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This includes the effects of both naturally and anthropogenically driven climate change:
Warmer atmosphere
Warmer oceans
Ice caps melt
Increases volume of water in sea
SL increases globally (eustatic SLR)
High and low energy coastlines
Low Energy coasts
Constructive waves
Hige enegy coast
Depositional and Transport
Form beaches, spits, salt marshes and sand dunes
located on low land coasts or on costal plain landscapes
Eg: Mediterranean coasts, East Anglian coasts
Sediments from eroded land
Form cliffs, wave cut platforms, sea caves, arches, stacks
Destructive waves
Located on rocky landscapes and on both highland and low land coasts
Eg: Atlantic coasts of Norway and Scotland