Studied by 0 peopleWaves
Waves are formed by wind blowing over the sea surface.
the fetch
The distance a wave travels before reaching land
The longer the fetch...
the stronger the wave
the swash
the water that rushes up the beach when a wave breaks
the backwash
the water that returns back down the beach after the swash
Constructive waves
Waves in which the swash is greater than the backwash.
Destructive waves
Waves in which the backwash is greater than the swash.
Hydraulic Action
The physical force of the waves breaks material off the coastline.
Abrasion
Loose material is thrown against the coastline by waves and this action breaks more material off the coastline.
Compression (Compressed Air)
When waves crash against a cliff, air gets trapped in the cracks on the cliff face and becomes compressed. When the waves retreat, the pressure is suddenly released, and this creates a mini shockwave. This compression and release happens repeatedly until the rock eventually shatters.
Solution
Some rocks, such as limestone and chalk, are dissolved by acids in the sea water.
Attrition
The stones that are carried in the waves are constantly hitting against each other. Over time, they become smooth and rounded. This can eventually lead to the formation of sand.
A bay
a curved opening into the coastline where waves have eroded softer rock.
A headland
a narrow finger of rock sticking out into the sea
bays and headlands formation
waves crash against coastline, soft rock erodes faster than hard rock, hydraulic action wears away and breaks off bits of the softer rock, the sea uses the stones it carries to hit off and wear down the coastline, water fills in the place where the soft rock used to be to form a bay, the harder rock remains resistant to erosion and stands out on either side of the bay to form headlands
example of bay
bantry bay
example of headland
missen head
A sea cliff
a vertical or steep slope on the coastline
a sea cave
a tunnel at the base of a cliff
A sea arch
an arch-shaped tunnel that stretches through a headland
A sea stack
a pillar of rock cut off from the cliff or headland and left standing on its own
A blowhole
a passage that links the surface of the cliff top with the roof of a sea cave.
longshore drift
when the sea transports sand and sediment in a zig-zag pattern down along the shore
A beach
a build-up of sand and shingle that has been deposited by constructive waves between the high-water and low-water mark
beach formation
the swash carries material up the shore and deposits it, the waves are unable to carry all the material back because the back wash is weaker than the swash, the heaviest material is dropped first, at the top of the beach and the finer material is carried back down, closer to the shoreline, over time, this material builds up
beach example
Rosslare in Co. Wexford
A sand spit
a long ridge of sand or shingle that stretches across a bay and is connected to one side of the bay
A lagoon
an area of water that has been cut off from the sea by a sandbar
A tombolo
a ridge of sand that connects the mainland to an island
3 ways that people use the sea
food supply, recreation, transport
what is a sea wall
a wall that breaks the power of incoming waves, their curved tops push waves back out to sea
what is rock armour
large boulders at the bottom of a cliff or in front of a sand dune
what are groynes
concrete or wooden structures built at right angles to the coastline
what are gabions
wire cages filled with small stones
Note 
Flashcard (102)