factors effecting coastal erosion Flashcards
hydraulic action
impact on the rocks due to the sheer force of the water itself. this exerts a lot of pressure upon the rock surface.
quarrying (cavitation)
super fast hydraulic action.
breaking wave traps air a it hits the cliff face. the force of the water compresses the air into any gaps the rock has, exerting a force causing erosion.
abrasion/corrasion
material the sea picked up also wears away at the rocks face as its hurled at it
attrition
the rocks in the sea that carry out abrasion are slowly worn down into smaller more rounded pieces.
corrosion/solution
the dissolving of calcium based rocks eg. limestone.
what’s a process?
action that changes an environment
what’s a factor?
circumstance which helps determine which processes are most likely to take place. eg. wave refraction, lithology, geology.
geology- factors that determine erosional processes
lithology refers to the physical properties of the rock, such as the resistance to which it erodes. hard rocks are resistant to weathering and erosion, so a granite coastline will erode a lot slower than boulder clay coastline.
granate- 1mm a year, limestone-1cm a year, boulderclay-10m a year.
human intervention- factors that determine erosional processes
groins, sea walls, rock armour,gabions,reventment etc all decrease erosional processes
waves- factors that determine erosional processes
depends on;
FETCH SIZE, DIRECTION OF PREVAILING WIND, WIND DURATION, WIND ENERGY.
rock faults- factors effecting erosional processes
fissures, joints, cracks are weaknesses in rocks, therefore the more there are, the rate of erosion increases. this could erode into headlands.
differential erosion
the rate of erosion varies due to varying geology of rocks and varying resistance.
factors that effect erosional processes
orientation
bedding structure
landforms of coastal erosion.
CLIFF
WCP
H&B
GEOS
BLOWHOLE
CAVE
ARCH
STACK
STUMP
how do WCP form?
an example of a scp is flambrough head.
the weather weakens a fault in the face of the cliff.
waves attack the base of the cliff via processes such as wave quarrying and attrition, which forms a wave cut notch.
the notch deepens, and increases in size, causing the cliff to be unsupported and collapse.
the waves carry out the eroded sediment forming a wcp.
the process repeats and the cliff retreats.
