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Flashcards in Features of coastal erosion/deposition Deck (12):
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cliff (erosion)

-A feature of coastal erosion is a cliff.
-An example of cliffs are the cliffs of Moher.

-Waves crash against the coast which is made of hard rock and soft rock.
-The soft rock is eroded faster than the hard rock by hydraulic action (force of the waves) and abrasion (rocks scratching the surface)
-A notch is cut out in the soft rock.
-This notch gets bigger to form an overhang.
-Over time the overhang becomes unstable and collapses.
-Some of the large rocks are dragged out to sea scratching the bed making a wave cut platform.
-The process repeats itself

1

Headland + Bay (erosion)

-A feature of coastal erosion are headlands and bays.

-A bay is a wide, curved opening into the coast.
An example of a bay is Dublin bay.
-A headland is a neck of high land that huts out into the sea.
An example of a headland is the Mizen Head.

-The soft rock (eg shale) is eroded quickly and a bay is formed.
-The hard rock (eg sandstone) is eroded much slower and stands out as a headland.

2

Sea cave (erosion)

A tunnel found in a cliff formed by hydraulic action, abrasion, etc.

3

Sea arch (erosion)

Formed when the sea cave cuts through the other side.

4

Sea stack (erosion)

Formed when sea arch collapses.

5

Sea stump (erosion)

Formed when sea stack is eroded.

6

Blowhole (erosion)

Passage that links the roof of a cave with the surface of the cliff top.

7

Longshore drift (deposition)

Longshore drift is angular/zig zag movement of material along the shore.
The direction that the material moves is affected by the prevailing winds.

8

Sand spit (deposition)

-A ridge of sand or shingle that is connected to the land at the end and extends into a bay or estuary. eg sutton in dublin

-It is formed when large amounts of material are moved along the coast by longshore drift.

-As it loses energy it deposits material on the sea bed.

-The deposits buiod up to rise above the level of the water.f

9

Tombolo (deposition)

A ridge of sand and shingle (sand spit) that extends from the land (coast) to an island. eg. Howth in Co. Dublin,

10

Lagoon (deposition)

Formed when a sand spit (sand bar) extends from one headland across a bay to another headland and blocks a body of water.

11

Beaches

-A beach consists of sand a shingle.

-Fine material is found at the lower part of the beach.

-Coarse material is deposited at the upper beach.

-In stormy weather the swash is strong enough ti hurl large stones and rocks up past the normal high tide mark where they remain to form a storm beach.

-Finer material is found at the lower part of the beach each due to erosion (eg attrition)

-Sandy beaches can be seen at curracloe in co. wesford,
storm beaches can be seen at garretstown co. cork