The Sea: Erosion and Deposition

How does the sea erode coastal areas?

hydraulic action, abrasion, attrition

What is hydraulic action

waves compress air against the cliff face; as waves retreat from the coastline, the pressure is released sucking rock pieces away

corrasion

rock from the cliff face is a cannon ball to further batter the cliff face

attrition

rock fragments wearing one another down

wave cut platform

new area of land that replaces the cliff as it retreats; raw beach

Speed of cliff retreat depends on:

rock type, wave strength, tidal currents,

Name three rock types that erode quickly under sea action

chalk, clay, sandstone

rock type that erodes slowly

granite

Where does beach material come from?

eroded cliffs, headlands and rivers near the coast

What are headlands?

protruding segments of the coastline that form as softer rock around them is eroded

What features are formed (in order) to create a stack

joint, cave, blowhole, arch, stack

Beaches are often made of the same rock material as the ________________________________

nearby cliffs and headlands

longshore drift aka

littoral drift

longshore drift has a ________ pattern

zig zag

why are groynes built?

to stop longshore drift and keep sand on the coast

What is a storm beach

ridge of large boulders and pebbles thrust further inland due to stormwaves/ high tides

bar aka

barrier beach

bar

sandspit that connects one headland to another headland