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
what is a concordant coastline
the same type of rock faces the sea
forms coves
what is a spit
sand/shingle beach joined to land but stretches downdrift into sea
formed when coastlines change shape
what is a bar
ridges of sand stretching from one side of the bay to another
what is a tombolo
spit that joins the headland to an island
what is a wave cut notch
undercutting of cliff due to abrasion and hydraulic action
what is a wave cut platform
narrow, flat area of bedrock at the base of the cliff, visible at low tide
formed due to erosion
what is a cove
indentation on the coast on a concordant coastline
what is a beach
area of deposition
what is a headland
cliff that juts out into the sea so surrounded by water on 3 sides
disconcordant coastline
what is a bay
crescent shaped indentation in the coastline between 2 headlands
what is a rockpool
hollowing wave cut platform due to abrasion
what is a bedding plane
horizontal line of weakness
define arches
a wave-eroded passage through a headland, connected to headland with unsupported top
define stacks
an isolated pillar of hard rock left when top of arch collapses
define stumps
the base of a collapsed stack, visible at low tide
