waves and the coast
waves and coast
definitions
coast
waves
the transition zonebetween the land and the sea
factors affecting the coast can be
human activity
sea
weather and climate
land
a long body of water curling into an arched form and breaking on the shore. They erode, transport and deposit materials
waves are created by winds, the wind makes friction with the sea creating a wave, this is why the power of the wave is the power of the wind, it as well depends on the length and time it has been affected by the wind, this factors are called fetch
terminology of waves
wave length
wave height
wave frequency
velocity
fetch
swash
backwash
the distance between 2 successive waves
distance between the through and the crest
crest
through
lowest point of the wave
highest point of the wave
the movement of water down the beach
the amount of water over which a wave has passed
number of waves per minute
the speed of the traveling wave
the movement of water up the beach
constructive and destructive waves
destructive waves
remove sediment from the beach. They have a short wave length, normally occur on steep gradients and have a circular orbit. High wave height. Weak swash, brings little material, strong backswash which removes a lot of sediment.
wind strendth, rainfall
settlement, development
water depth, ecosystem
ecosystem, river sediment
there are 3 main processes happening along the coast
erosion
the wearing away of rocks by wind and rain
types of costal erosion
hydrolic action ( wave hit wall)
attrition (rock hit rock)
abrasion(Rock scratch rock)
solution (dissolve rock)
the sheer power of the waves repeatedly forcing water and air bubbles into cracks in the rock
longshore drift
when a rock becomes eroded off a cliff or a rock the waves can move it along the beach, this is called longshore drift. (the smaller the material the faster it will move)
diagram in comments
when the sand particles and stones hit against each other and are broken into smaller particles
weathering
mass movement
when the salt and chemicals in the seawater dissolve away the rocks that the shoreline is made up of
when the stones in breaking waves wear against rocks
types of weathering
physical
biological
chemical
onion skin weathering
when a rock repeatedly gets heated and cooled causing it to break down
freeze thaw weathering
happens when rainfall gets acumulated inside rock cracks, this water then freezes and makes the crack expand. This repeated process will cause the rock to break down.
weathering that is caused by plants or animals, for example a seed falling into a crack expanding the crack as the plant grows
physical and biological weathering are types of mechanical weathering
a chemical reaction that changes the nature of the rock causing it to break down
the removal of cliff based materials by gravity
landslide
mudslide
rock fall
slumping
the downslope movement of discrete blocks of rock down a flat/linear slip plane, maintaining contact with the cliff surface throughout
a rock fall involves fragments of rock breaking away from the cliff face, often due to freeze-thaw weathering
occur when saturated soil and weak rock flow down a slope.
Slumping is a rapid movement of a mass of earth or rock sliding along a concave surface.
constructive waves
deposit sediment to the beach, they have a long wavelength, normally in shallow gradients and have an elliptical orbit. Low wave heights, strong swash carries sediments, weak backswash removes very little material
the movement of material along a coast by waves which approach at an angle to the shore but recede directly away from it.
Process of transportation
Suspension
Solution
Saltation
Traction
prevailing wind
a wind from the direction that is predominant or most usual at a particular place or season.