COASTS Flashcards
Erosion
Displacement of solids.
Usually by wind, water or ice.
Happens because of gravity or by living organisms
Weathering
Process of weakening and breaking up rocks. Physical and chemical breakdown of rocks and materials at or near the earths surface
Different types of weathering
Physical
Chemical
Biological
Mass movement
Downhill movement of westered material under the force of gravity
Speed can vary
Slumps, slides, mudflows
Wave quarrying
When high energy waves hit thee cliff face
They have the energy to remove chunks of the cliff.
Occurs due to intense force
Cavitation
Similar to hydraulic action
Wave smash into a crevice.
It compresses air bubbles that fizz.
Makes the cliff recede.
Creates a mini explosion
Sub-aerial processes
The processes of weathering and mass movement
Mechanical weathering
Involves the break-up of ricks within any chemical changes taking place
Types of mechanical weathering
Littoral zone
Coastal zone
Sediments are moved. Around between land, beach and sea
Backshore
The beach, not reached by the sea in normal conditions
Foreshore
Smash zone
Offshore
At sea
Some distance from the shore
Concordance coastline
Layers of rock are parallel to the direction of the coastline
Disconcordant coastline
Layers of rock perpendicular to the coastline
Creating headlands and bays
Dalmatian coast
Submergent landscape
Ridges and valleys running parallel to the coast
Folding
Bending of rock layers due to stress in the earths crust
Igneous rock
Rock that forms from the cooling if molten rock at or below the surface
Sedimentary rock
Rock formed from sediments, plant or animal remains
Experiencing high heat or pressure
Un consolidated
Loose
Incoherent
Strata
Layers of rock
Permeable
Water can pass thru
Impermeable
Water cannot pass thru
Constructive waves
Low wave that deposits material
Swash stronger than backwash
Destructive wave
Found on steep beaches
Backwash stronger than swash
Hydraulic action
Large destructive wave breaks on the cliff
Force of water creates pressure in cracks in the cliff and produces an explosive force
Breaking material away from the cliff
Corrosion
Acidic sea water reacts with minerals in the cliff face and weakens it
Abrasion
The grinding away of rock by other rock particles carried in water, ice or wind
Attrition
Wearing down over time
Wave cut notch
A notch in a coastal cliff cut out by wave erosion
Wave cut platform
Wide, gently sloping rocky surface at the foot of a cliff, produced by cliff recession
LSD
Movement of water and sediment down a beach caused by waves coming in to shore at an angle
Barrier beach
Forms when storm waves pile up large amounts of sand above sea level forming a long narrow island parallel to the coast
Tombolo
Ridge of sand that connects an island to the mainland or to another island
Sediment cell
Stretch of coastline
Associated nearshore area within which the movement of coarse sediment, sand and shingle is largely self-contained
Source
Where the sediment within a cell is supplied from
Transfer
Move from one place to another
Positive feedback
Feedback that tends to magnify a process or increase its output
Negative feedback
Type of regulation that responses to a change in conditions by initiating responses that will counteract the change
Maintains a steady state.
Recession
Backwards movement of coastline
Emergent coast
Stretch of coast that has been exposed due to changes in sea level
Rias
Drowned river valleys
Dredging
Clearing the bed of an area of water by scooping out beach material and moving elsewhere
Coastal management
Strategies used to defend coastal environments
Divided into 3 approaches: hard, soft engineering and managed Retreat
Sub areial processes
Weathering and mass movement
Hard engineering
Building artificial structures such as as sea walls aimed at controlling natural processes
Invasive method to prevent coastal flooding and erosion
Groynes
Wooden or concrete barriers at right angles to the beach
rip rap
Aka rick armour
Large rocks at food of sea walls or cliffs made to absorb waves
Cheap and have a long lifespan
Soft engineering
Managing erosion by working with natural processes to help restore beaches and coastal ecosystems
More sustainable method
Beach nourishment
Large quantities of sand are added to the beach system to offset losses caused by wave erosion
Cliff regrading and drainage
Creating a stable rock slope on a cliff to enhance stability
Provides drains to prevent upper rock layers becoming saturated with water and subject to mass movement
Dune stabilisation
Planting more grass and leaving driftwood to allow more sand to be deposited from the wind
Hold the line
Employing coastal defence strategies to maintain the coastline in its current position
Advance the line
Coastal management strategy which involves pushing the coastline further towards the sea
Flamborough chalk cliffs
Sedimentary sock
Holderness coast
More resistant to erosion
Have vertical cracks
Cracks are regularly formed in more resistant rock that forms headlands
Coastal recession at Holderness coast
Fastest rate of erosion in Europe
Social: unprotected villages near the cliffs
