๐๐๐จ๐ ๐ซ๐๐ฉ๐ก๐ฒ ๐ Flashcards
explain the sea coastline
the sea is constantly shaping the coastline. Waves erode, transport and deposit materials along the coast
explain how the wind is relevant towards the sea
waves are formed by wind, moving across the surface of the sea. The distance of open sea over which the wind blows, is called FETCH. Waves with a fetch are stronger
Explain what happens when the shallow water is reached
When we reach shallow water, the front of the waves melt the sea bed, causing it to break as it moves toward the shore
Explain backwash and swash
When a wave breaks, the water that rushes up the beach is known as the SWASH. The water that runs back down the beach is known as BACKWASH
How much of the earth is water?
70%
What impacts the size of a wave?
Wind impacts the size of the wave.
Explain constructive waves (2)
Waves in which the swash is greater than the backwash
But the backwash is weak and cannot carry the sand and stones away again. So the coastline builds up. Typical on calm days
Explain destructive waves (2)
Waves in which the backwash is greater than the swash. Destructive waves erode material and carry it away
They have a powerful backwash that can drag stones, sand and people back into the water but their swash is weak
Explain all 3 points on the cliff erosion
1) destructive waves crash against the base of the cliff, weakening the rock.
2) a notch is eroded at the base of a cliff over time by the processes of waves erosion. Continued erosion causes the notch to grow
3)the headland hangs overhead until the notch becomes so deep that the overhanging land collapses and falls into the sea
What is transportation referred to?
Transportation refers to the movement of eroded material by the sea
How does transportation work?
The swash and backwash of waves carry material onto and off beaches
What is longshore drift?
Longshore drift is the transportation of material up and down the coast in a zig-zag pattern
Name the 2 steps for longshore drift
1) Waves approach the coast at an angle, due to wind direction, carrying material to the beach.
2) the backwash then carries the material back to sea in a straight line
EXAM ANSWER ON WAVES
Waves approach the coast at an angle because that is the direction the wind is blowing. Material is carried towards the coast at this angle by the swash of a wave and then dragged back out to sea in a straight line by wave backwash. This transportation of material up and down the coast in a zig-zag pattern is known as longshore drift
Explain sea arch
Are formed when a cave continues to be eroded and expanded until it cuts right through a headland
Explain sea stack
A column of rock standing in the sea, remaining after erosion of cliffs
Explain hydraulic action
When the force of the waves erode the coast as they crash against it
Explain abrasion
When eroded material in waves crashed against the coastline
Explain Attrition
When the seas load hits and collides against itself due to ocean currents
Explain solution
When some of the seas load is dissolved by water
Explain the geographical term for compressed air
Created when waves crash against the joints and cracks in the coastline
Explain the (3) landforms of marine deposition
Beach and sand dunes
Sand pit and lagoon
Tombolo spit
Explain the 5 terms of deposition on beach
1) When a constructive wave hits the shore, its strong swash carries small stones and sand up as far as the wave will reach. The wave runs out of energy and deposits its load.
2) itโs weak backwash drags only the smaller, lighter particles back to the sea, leaving the heavier stones higher up the shore.
3) in times of storms, destructive waves will throw much larger boulders and stones to the top of the shore which are left as a storm beach.
4) when the tide is out, the beach sand is dried by the wind and is blown to the back of the beach where it is deposited into sand hills called sand dunes
5) sometimes people plant marram grass to stabilise sand dunes so that they donโt move inland and cover farmland
Bay definition
A large, eroded area that has filled with water, partially surrounded by more resistant rock of the headlands
Headland definition
Land made of hard rock that is more resistant to erosion, which extends out into the sea
Geo definition
a gap in the headland where a blowhole and a cave once existed