Coasts Flashcards
What is hydraulic action
Is when waves crash into the cracks in a cliff, it compresses air into the crack. Eventually the crack will get bigger and pieces of rock will fall off
What is corrasion
Is when material such as sand,shingle and pebbles that’s the wave carry are hurled against the cliff, overtime pieces of rock break off. This is known as the sand paper effect.
What is corrosion
This is when salt and other chemicals in the sea slowly dissolve the rock.
What is attrition
This is when beach materials run against each other to wear themselves down.
What is the formation of a sandspit
Is when beach material is transported along the coast by longshore drift, a ridge of sand builds up and outwards forming a spit. If the spit extends across a bay it can join up with a beach on the other side forming a sand bar, this encloses a lagoon on the landward side of the bar. Some coastlines sand spits may grow outwards into open water and reach an island forming a tombolo.
What is the formation of a beach
Beaches are made of soil,rock fragments that have eroded from cliffs, these fragments are then broken into smaller pieces. The eroded material deposited where the waves have little energy forming a beach.
What is longshore drift
Is when waves approach the beach at a similar angle to the prevailing wind, waves break and the swash carries materials up the beach at the same angle as the wave. The backwash and any material carried by it returns by the shortest route at right angles to the beach this process gradually moves the material along the beach in a zigzag pattern.
What is the formation of a cave/arch/stack and stump
Waves crash into headland eroding the weaker parts such as cracks the are eroded by 3 different processes hydraulic action,corrosion and corrasion. The cracks get deeper and wider, developing into a cave,overtime the horizontal erosion of a cave may cut through a headland to the other side forming an arch.
What is the formation of a headland and bay
They are formed along coats that are made of alternative bands of hard and soft rock, this is called discordant coastline,due to differential erosion,the waves erode the softer rock more quickly forming a bay and the harder rock more slowly forming a headland. Overtime the bays will become more sheltered and sandy beaches will form
What is the formation of a wave cut platform
A notch is cut into the base of a cliff by waves,overtime the notch gets bigger due to hydraulic action. Eventually the unsupported rock will fall due to gravity, the sea will remove the debris, eventually the wave cut platform will be in front of the cliff.
