Coastal processes
The uninterrupted distance that a wave travels and builds up energy
What is the fetch?
13
How many sediment cells are there in the UK?
sub-aerial weathering - biological, mechanical and chemical
What processes break down rock to make the coastline more vulnerable to erosion?
LSD moved material along a beach until a change in coastline means the material becomes deposited. Over time wave action curves this feature and creates a sheltered salt marsh behind it.
What is a spit?
A raised beach created by sea level change (emergence)
What do we find at Portland Bill?
low frequency, low waves, strong swash, weak backwash, deposits sediment
What are the characteristics of a constructive wave?
rivers, sea bed, coastal erosion, offshore deposits
What are the sources of sediment in a cell?
Rotational slumping, slipping, landslides, rockfall, mudflows
What are examples of mass movement caused by gravity and undercutting of cliffs or gravity and water?
A tombolo created when deposition joins together Weymouth and the Isle of Portland
What is Chesil Beach?
changes in the height of the land relative to the sea level. These are localised changes
What is isostatic sea level change?
the process of moving sediment along a beach by swash and backwash
what is Longshore drift?
A closed coastal system
What type of system is a sediment cell?
Geo, cave, arch, stack...
What are the stages of a stump formation?
A ridge of sand and pebbles found on a beach at high tide marks when the waves lose energy
what is a berm?
a drowned glacial valley (submergence)
What is a fjord?
abrasion, attrition, hydraulic action, quarrying, solution and cavitation
What are the coastal processes of erosion?
It sits between 2 headlands or peninsulas and material moves within it
Why is a sediment cell self-contained?
where we find horizontal bands of rock are eroded at high tide leaving a platform behind at low tide known as a wave cut platform
What is Kimmeridge Bay an example of?
a sheltered bay where sediment is deposited as the energy for transportation decreases. Often found behind a spit or where a river meets the sea.
What is a salt marsh?
Uplift causes eustatic changes - rises in sea levels under the ocean or isostatic changes - rises or falls in land
How can tectonic changes impact on sea levels?
wind moves and deposits dry sand along a beach
What is aeolian deposition and transportation?
More erosion due to extreme weather and sea level rises, stronger winds mean more transportation of sediment
How will climate change impact a sediment cell?
Swanage Bay and the surrounding headlands are created by differing rates of erosion on different types of geology on this type of coastline.
What is a discordant coastline?
The LSD and deposition of sediment along Chesil Beach trapping a series of lagoons between it and the sea
A Bar
increased coastal erosion and removal of beach sediment, flooding of the quayside and marina, increase costs of coastal management
How will Weymouth be affected by climate change?