coasts (paper 1) Flashcards
what is the coast
where the sea meets the land
how are waves caused
they are created by the action of wind blowing over the surface of the sea
how does wind create waves
the wind causes friction on the surface of the wave
this creats the circular motion of a wave
what is the swash
movement of a wave up a beach
what is backwash
movement of a wave back down the beach
what causes a wave to break
friction at the base of the wave
what is the fetch
the distance of which wind blows
what decides the energy of a wave
- velocity of wind
- duration of wind blowing
- fetch
what are the two types of waves
constructive
destructive
describe the characteristics of a constructive wave
- big wavelength
- strong swash
- weak backwash
- low frequency
- small fetch
what do constructive waves do
they build wide sandy beaches with a gentle gradient, depositing sand
describe the characteristics of a destructive wave
- big waveheight
- small wavelength
- bigger fetch
- weak swash
- strong backwash
what do destructive waves do
they destroy the beach giving it a harsher gradient, erosion is dominant
define erosion in the terms of coasts
the proces of wearing away the land by waves
what are the four types of erosion
- solution (chemical)
- abrassion (rubbing)
- hydrolic action (power)
- attrition / corrosion (rocks)
what is solution erosion
chemicals breaking down geology
what is abrassion erosion
when sediement in waves rub against the coast
what is hydrolic action erosion
the force of compressed air are the waves hit the coast, weakening the rock
what is attrition erosion
when big rocks break each other down into smaller rocks
why does deposition happen
the waves lose energy, dropping the sand, rock particles and pebbles it carries
when is deposition most likely to occur
- waves enter a shallow area
- waves enter a sheltered area
what are the four types of transportation
- solution (cannot see)
- suspension (floating)
- saltation (bounce)
- traction (roll)
what is long shore drift
the movement of sediment along the coast laterally
what labels are needed in an LSD disgram
- swash
- backwash at 90degrees
- direction of LSD
- prevailing wind
what is weathering
the breakdown or decay of rocks by natual processes in situ
what are two examples of physical weathering
- freeze thaw
- exfoliation