3 Physical Landscapes (coastal keywords) Flashcards Preview

GCSE Geography > 3 Physical Landscapes (coastal keywords) > Flashcards

Flashcards in 3 Physical Landscapes (coastal keywords) Deck (26):
1

Swash

Movement of a wave into the beach.

2

Backwash

Movement of a wave back into the sea.

3

Crest

The top of the wave.

4

Trough

The back of a wave.

5

Wave Height

The vertical distance from trough to crest.

6

Wave Length

The horizontal distance between two crests.

7

Wave Frequency

The number of waves breaking per minute.

8

Mechanical Weathering

Water gets into the cracks and joints in the rock, and as it freezes, the volume expands. This puts pressure on the surrounding rock and the crack is widened.
This is called ‘freeze-thaw action’. Over time the size of the crack increases, until a block of rock breaks off.

9

Chemical Weathering

This occurs when water reacts with the calcium carbonate in rocks like limestone and chalk. The calcium carbonate dissolved and is washed away in solution, weakening the rock.

10

Biological Weathering

Due to the actions of flora and fauna. Plant roots grown in cracks in the rocks. Animals suck as rabbits burrow into weak rocks.

11

Sliding

This is when large chunks of rock slide down the slope quickly without any warning.

12

Slumping

This is common when the cliffs are made of clay. The clay becomes saturated (soaked with water) during heavy rainfall and oozes down towards the sea.

13

Rock Fall

Fragments of rock break away from the cliff face.

14

Discordant Coastline

Coastlines where the geology alternates between bands of hard rock and soft rock.

15

Concordant Coastline

When a Coastline has the same type of rock along its length.

16

Soft Engineering

Working with nature to help maintain the present coastline.

17

Hard Engineering

Man-made structures built to ensure total protection of the present coastline.

18

Manages Retreat/Realignment

Do nothing and allow present coastline to change.

19

Sea Wall

Hard Engineering.
A concrete wall designed to reflect the waves back out to sea and/or absorb their energy. Sometimes has a promenade built on it.

20

Groyne

Hard Engineering.
A wooden or stone groyne is built in the beach at right angles to the coast they stop long shore drift by trapping sediment, building up the beach.

21

Rock Armour

Hard Engineering.
Big boulders places at the base of the cliff - dissipate the energy of the waves.

22

Gabion

Hard Engineering.
Steel wire mesh cages filled with pebbles or rock at the back of the beach to create a low wall-like structure. Cages absorb some of the energy.

23

Beach Nourishment

Soft Engineering.
Replacement of lost sediment. A nourished beach means fewer waves reach the bank of the beach. As more wave energy is absorbed and dissipated by the beach, the rate of erosion is reduced.

24

Beach Re-profiling

Soft Engineering.
Artificial reshaping of a beach using existing material. Beach is lowered in winter destructive waves. After storms, bulldozers move shingle back up the beach. This ensures the beach is large enough to be an effective buffer.

25

Dune Regeneration

Soft Engineering.
Artificial creation of new sand dunes or restoration of existing dunes. Physical barrier between sea and land.

26

Longshore Drift

The prevailing winds make the swash angle to the shore. Backwash is at a right angle because of gravity. Longshore drift therefore moves material in a zig zag movement along the beach.