Chapter 10 Coastal

Question 1

Define contructive waves

Answer 1

Constructive waves deposit more then they take away, this usually happens when the swash is more powerful than the backwash

Question 2

What are destructive waves?

Answer 2

Destructive waves erode more then they deposit, this usually happens when the backwash is stronger then the swash

Question 3

What is a fetch?

Answer 3

I fetch is the length of water the wind can run over

Question 4

What is hydraulic action

Answer 4

Hydraulic action is erosion carried out by the force of waves crashing and pouding against the coast line. Air is trapped in cracks and compressed and when the pressure is released it causes a mini explosion

Question 5

What is abrasion

Answer 5

Abrasion is when the sea uses its load to wear away at the coast

Question 6

Attrition

Answer 6

Attrition is when the sea load smashes against eachother to make smaller smoother rocks

Question 7

How are bays and headlands formed

Answer 7

Bays and headlands are formed when the sea erodes a coastline with bands of soft and hard rock. The soft rock erodes faster and creates a bay

Question 8

Define faults and joints

Answer 8

Faults and joints are weaknesses in the rock

Question 9

How are cracks formed

Answer 9

Faults and joints widen into cracks by the power of the waves

Question 10

How are caves formed

Answer 10

When cracks widen into caves

Question 11

What are are blowholes and how are they formed

Answer 11

Blowholes are openings in the roof of a cave where sea spray is thrown up through in storms. Faults and joints are weakened to form a hole that reaches the surface

Question 12

How are arches formed

Answer 12

When two caves join back to back

Question 13

When does longshore drift occur?

Answer 13

Longshore drift occurs when waves hit the beach at an angle and retreat straight back down

Question 14

How do people control longshore drift

Answer 14

Groynes, wooden barriers built straight across the beach, they trap sand as its being transported along the beach

e.g South Wexford coast

Question 15

How does the sea help people?

Answer 15

• tourism: many people enjoy going to the seaside which has led to the development of seaside resorts, holiday homes and local shops
• recreation: used for halting, fishing, swimming and coastal walks
• ports such as Dublin are used to import and export goods and are also ferry services to Britain and France
• fishing industry: large fish catches by trawlers provide food and these trawlers are serviced by ports such as Killybegs
• oil and gas: deposits of oil and gas are under the sea floor

Question 16

How do people harm the sea

Answer 16

Pollution: untreated sewage is pumped into the sea and oil spills from ships and pipelines pollute the water. These endanger wildlife and sea life

Question 17

How does the sea harm people

Answer 17

• coastal flooding: huge waves may flood low-lying areas such as the Netherlands
• 1953 a storm surge flooded the Netherlands an 1800 people died and hundreds of thousands displaced
• erosion of the land: cliff collapses are dangerous
• tsunamis

Question 18

What are sea walls

Answer 18

Concrete walls to help protect land and towns from flooding. There are often curved to throw the sea back at itself

Question 19

What are the different ways of protecting against coastal erosion/defending the coast?

Answer 19

• sea walls
• gabions
• rock armour
• marram grass
• groynes

Question 20

What are sea walls?

Answer 20

Concrete walls built to protect lands and towns from flooding and attack from the sea. They are often curved at the top to throw water back at the sea

Question 21

Gabions

Answer 21

Wire cages filled with rocks to lessen the power of the sea

Question 22

Rock armour

Answer 22

Massive rocks piled along a beach to protect sand dunes and the coast

Question 23

Maram grass

Answer 23

Maram grass is grass grown in sandunes by the local council to catch the sand and stop it from going inland

Question 26

What are the problems, with longshore drift?

Answer 26

• longshore drift carries silt from the mouths of rivers and sand into harbours and estuaries which can block them up
• it removes sand from beaches which can damage tourist industry

Question 27

What are sea stacks?

Answer 27

Sea stacks are formed when the roof of an arch collapses i

Question 28

What are sea stumps?

Answer 28

Worn-down remains of a sea stack

Question 29

How are beaches formed?

Answer 29

A beach stretches along the shore and is composed of sand and shingle that have been deposited by the waves between low and high tide

Question 30

What is the storm beach made up of?

Answer 30

Composed of bigger stones and rocks deposited at the back of the beach above the high water mark during a storm

Question 31

What are the feature of sand deposition?

Answer 31

• beaches
• sand spits
• sandbars
• lagoons
• tombolos

Question 32

What is a sandspit?

Answer 32

A landform made mostly out of sand and it attached to the land at one end.

• formed by longshore drift which deposits sand where the coast changes direction and the waves lose their power
• occurs at river mouths and headlands

Question 33

What is a sandbar?

Answer 33

Formed when a sandspit stretches across a bay and connects the two sides
-happens when there is no river flowing into the bay

Question 34

What is a lagoon?

Answer 34

A shallow area of seawater that is cut off from the sea by a sandbar and will eventually dry our

Question 35

What is a tombolo?

Answer 35

Formed when an island is connected to the mainland by a sandspit

Question 36

What is a cliff?

Answer 36

A vertical height of rock along the coast

Question 37

How are cliffs formed/how do cliffs retreat?

Answer 37

1. The waves erode and undercut the base of the cliff using hydraulic action and abrasion
2. A wave-cut notch is formed at the base of the cliff, between the high and low water marks, which undermines the rock above.
   3 The face of the cliff falls down.
   4 A wave-cut platform (or rock platform) is formed as the cliff retreats.

Example: cliffs of Moher