Coastal retreat Flashcards
What physical factors affect coastal retreat?
Geology Fetch Waves Wind direction Seasons Weather systems
What is the fastest eroding coast in the UK
Holderness Coast
How does Fairly resistant chalk contribute to erosion on Holderness Coast?
Fairly resistant chalk- Explains the presence of Flamborough Head, a headland. Horizontal bedding planes produce steeply sloping cliffs. Waves exploit natural weaknesses (faults/joints) in this sedimentary rock allowing for the formation of caves, arches, stacks and stumps.
How is fairly weak glacial till a factor at Holderness Coast?
A mix of clays, sands and silts was deposited after glaciers retreated.
Produces shallow, sloping cliffs.
Easily eroded by marine processes and prone to slumping.
Eroding at 1.2 meters per year.
What two geological factors affect Holderness Coast?
Fairly resistant chalk
Fairly weak glacial till
What types of fetch and wave energy affect Holderness Coat?
Low pressure systems and winter storms
Destructive waves
Deep sea floor
Swell currents
How do Low pressure weather systems and winter storms affect Holderness Coast?
Produce locally strong winds and rains.
Air rises in low pressure systems causing much higher tides which reach the cliff foot.
How do destructive waves affect Holderness Coast?
They build up in enclosed north sea basin as swell energy cannot dissipate.
How does deep sea floor affect Holderness Coast?
Provides little friction to slow waves down.
How do swell currents affect Holderness Coast?
Swell currents from North Atlantic move around UK into North Sea basin, increasing wave energy.
How does longshore drift affect Holderness Coast?
Increases the rate of erosion and is the source of material for Spurn Head.
How do marine processes affect Holderness Coast?
Marine processes such as hydraulic action and wave pounding can hit the cliff foot directly at high tide as beaches are flat, bery thin and impermeable.
