Coastal Erosion

?
What is weathering?
Weathering is the breaking down of rocks in situ. There are three types: chemical, biological and physical. An example of weathering is freeze thaw. Freeze thaw is where water freezes inside a crack in a rock and then as it melts the crack expands.
1 of 16
What is erosion?
Erosion is the wearing away of coasts and cliffs with waves and movement. An example is abrasion where rocks are hurled and cliff face and grind down on the cliff like sandpaper and eventually wear it away.
2 of 16
What are characteristics of a destructive wave?
A destructive wave occurs at times of high sea gradient and discharge. They're normally over 1m in height but smaller in length. They occur with more than 10 per min. It has a weak swash but strong backswash which erodes the coast.
3 of 16
How does the sea erode the coast?
The coast is eroded with hydraulic action, abrasion and solution. Hydraulic action is where water enters gaps in the cliff which causes enough pressure for a minor explosion as the water leaves, the force of the water wears the coast away slowly too.
4 of 16
How does the sea erode the coast? Pt 2.
Abrasion is where materials such as rocks and pebbles rub along the coastline like sandpaper with enough force to wear the coast away. Solution is when acids in the water dissolve the coast and banks slowly.
5 of 16
How are coastal processes linked?
weathering + erosion -> transportation -> deposition
6 of 16
Explain the formation of a sea stack.
Lines of weakness form in headlands and hydraulic action and abrasion erode it away till it forms a cave. This cave is also eroded away and is widened and deepened. The sea cuts through the cave and forms an arch.
7 of 16
Formation of a sea stack pt 2.
The foot of the arch is eroded and the arch size grows. The rock and the material above the arch eventually collapses from loss of support and it leaves an isolated stack in the sea.
8 of 16
Name and describe two processes of coastal erosion.
Abrasion is where materials/rock/sediment and pebbles etc rub and hit against the coast with enough force to rub and wear it away. Solution is when acids in the water dissolve the coast.
9 of 16
How have processes of erosion created landforms
The cave is created through erosion - abrasion and hydraulic action which erode at the weakened lines in the headland. The hydraulic action puts pressure on the cliff face and creates minor explosions to weaken the rock.
10 of 16
How have processes of erosion created landforms pt 2.
Abrasion hurls rocks at the cliff face to break parts off and wear it away. The arch is also attacked by these types of erosion and attrition where rock particles hit against each other and smoothen the edges.
11 of 16
How have processes of erosion created landforms pt. 3
The headland is formed when the land on either side is made of weak and less resistant material which wears and erodes away quicker through abrasion. The stack is formed through abrasion and solution.
12 of 16
Long-shore drift diagram labels.
prevailing wind pointing in direction, hits at 45 degree angle. Gravity pulls it down at right angle/90 degrees. Swash is diagonal line, backswash is straight. Arrow showing direction of longshore drift.
13 of 16
How is a coastal spit formed?
Prevailing wind hits the coast and long shore drift occurs and moves sediment and material along the coast and the coastline changes direction and leaves a shallow area of water. Deposition then occurs in the water sheltered by the headland.
14 of 16
How is a coastal spit formed pt.2
The spit slowly builds up and extends in length so when the wind changes direction so do the waves meaning the spit forms a curve. A salt marsh begins to develop in the shallow water behind it. Spits can not grow across a river estuary.
15 of 16
describe the shape of the beach between two groynes
the beach builds in height eastward because of how long shore drift occurs and more sediment is deposited and there will be more material and sediment by the east groyne as it acts as a barrier.
16 of 16

Other cards in this set

Card 2

Front

What is erosion?

Back

Erosion is the wearing away of coasts and cliffs with waves and movement. An example is abrasion where rocks are hurled and cliff face and grind down on the cliff like sandpaper and eventually wear it away.

Card 3

Front

What are characteristics of a destructive wave?

Back

Preview of the front of card 3

Card 4

Front

How does the sea erode the coast?

Back

Preview of the front of card 4

Card 5

Front

How does the sea erode the coast? Pt 2.

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Geography resources:

See all Geography resources »See all Coastal environments resources »