river & coastal landscapes paper 1 Flashcards
what is swash
movement up the beach
(longshore drift)
what is backwash
movement down the beach
(longshore drift)
what is the prevailing wind
wind that changes the power of waves depending on distance it has been blowing for/power
why does a river cliff form on the outer bend of a meander
has less friction which uses more energy resulting in erosion by hydraulic action
why does a slip off slope form on the outer bend of a meander
there is more friction so there is less energy being used so the river deposits material on the outerbend causing slip off slopes
swash and backwash of a destructive wave
swash: weaker swash
backwash: breaks down the beach, stronger
swash and backwash of a costructive wave
swash:builds up the beach, stronger swash
backwash: weaker backwash
what is the fetch
maximum distance of open sea the wind can blow over
3 factors affecting the energy of the waves
speed of wind
time wind has been blowing
long fetch
what causes deposition to happen at the coast
sheltered bay-waves lose energy
constructive waves - weak backwash
large amount of sediment updrift
freeze thaw weathering
water goes into cracks, freezes and expands
biological weathering
weakening of rocks by plants, roots and animals
carbonation weathering
CO2 dissolves in water, makes carbonic acid and reacts with rocks containing calcium carbonate and dissolves them.
salt weathering
salt spray from sea goes onto rocks
the water evaporates leaving salt crystals
increased pressure on rocks
what is a discordant coastline
different types of rock faces the sea,
(soft rock, hard rock ect)
the soft rock is eroded, hard rock isnt
this forms headlands and bays
