Coasts Definitions

Question 1

Hydraulic action(Coasts)

Answer 1

the process by which waves break against the cliffs by their sheer weight and power(they also trap air in cracks in the rock, leading to the air being compressed by the waves, eventually causing the rocks to break apart)

Question 2

Corrosion/Abrasion(Coasts)

Answer 2

the process by which particles carried by the waves crash against the cliffs, eroding them

Question 3

Attrition(Coasts)

Answer 3

the process by which particles carried by the waves crash against each other and are broken up into smaller and rounder particles

Question 4

Solution/Corrosion(Coasts)

Answer 4

the process by which the acids in seawater slowly dissolve the chalk and limestone cliffs(the material produced is carried away by the process of solution)

Question 5

Constructive waves

Answer 5

low energy waves that have a long wavelength as well as a strong swash and weak backwash(they are usually associated with beach deposition)

Question 6

Destructive waves

Answer 6

high energy waves with a short wavelength as well as a weak swash and strong backwash(they are usually associated with beach erosion)

Question 7

Wavelength

Answer 7

the distance between 2 peaks/crests or 2 troughs on a wave

Question 8

Backwash

Answer 8

the retreat of a sea wave down the beach after the breaking of a wave

Question 9

Swash

Answer 9

the advance of a sea wave up a beach after the breaking of a wave

Question 10

Sedimentary rock

Answer 10

material that has been deposited by the force which originally carried it from elsewhere

Question 11

Bay

Answer 11

part of the sea that fills a wide-mouthed opening in the coastline

Question 12

Headland

Answer 12

a point of higher land jutting out into the sea, usually made from a resistant rock such as granite

Question 13

Longshore drift

Answer 13

the zig-zag movement of sediment along a shore caused by waves going up the beach at an oblique angle(swash), and returning at right angles(backwash)

Question 14

Sand spit

Answer 14

a long, narrow stretch of sand and/or shingle, with one end attached to the mainland

Question 15

Sand bar

Answer 15

a geographical structure that develops when a sand spit stretches across a bay linking two headlands(behind the sand bar, an area of water may be cut off from the sea to create a lagoon)

Question 16

Tombolo

Answer 16

a geological structure that forms when a beach or sand spit joins up with an offshore island

Question 17

Barrier islands

Answer 17

sandy islands that run parallel to the coastline forming a tidal lagoon between them and the shore

Question 18

Saltmarsh

Answer 18

a sheltered area, flooded at high tide, where silt collects behind a sand spit or sand bar

Question 19

Prevailing winds

Answer 19

the winds that blow into an area from a predominant direction

Question 20

Tsunami

Answer 20

a sea or tidal wave that is triggered by an undersea earthquake or volcanic eruption that displaces the water above it setting up a series of waves that build up to form a powerful devastating wave at the coast

Question 21

Discordant

Answer 21

referring to a coastline where the rock layers are at right angles to the coastline

Question 22

Concordant

Answer 22

referring to a coastline where the rock layers are parallel to the coastline

Question 23

Wave-cut platform

Answer 23

the narrow flat area found at the base of a sea cliff that was created by erosion

Question 24

Arch

Answer 24

a wave-eroded passage through a small headland

Question 25

Stack

Answer 25

a geographical landform consisting of a steep and often vertical column or columns of rock in the sea near a coast formed by wave erosion

Question 26

Stump

Answer 26

the eroded remains of a stack(often looks like a lump of rocks sticking up from its surroundings)

Question 27

Lagoon

Answer 27

an area of seawater separated from the sea by a narrow landform(eg. reefs, barrier islands, etc.)

Question 28

Subsidence

Answer 28

the gradual sinking/caving in of an area of land

Question 29

Seawall

Answer 29

a wall built to prevent the sea eroding an area of land(are often curved to reflect the waves)

Question 30

Groynes

Answer 30

barriers(usually made from wood) built at right angles to the beach to trap sediment and stop it being removed by longshore drift

Question 31

Rock armour

Answer 31

a barrier which consists of large boulders placed along the base of a cliff to absorb energy from waves

Question 32

Revetments

Answer 32

wooden or concrete slatted barriers placed at the top of beaches to protect the base of cliffs when the waves break against them

Question 33

Gabions

Answer 33

metal cages which enclose rocks and boulders to absorb the energy from waves

Question 34

Offshore breakwaters

Answer 34

large concrete blocks and boulders located offshore to reduce the power of the waves or to change their direction to reduce longshore drift

Question 35

Beach nourishment

Answer 35

a practice which involves replacing beach material that has been removed by erosion and longshore drift, and creating higher and wider beaches by transporting sand and shingle

Question 36

Managed retreat

Answer 36

a practice that involves allowing areas of coast to erode and flood, usually in areas where the land is of low value

Question 37

Halophytes

Answer 37

plants that need to live in salty water