Ch.11 The Sea/Coasts

Question 1

What is swash?

Answer 1

The white foamy water that flows up the beach when a wave reaches the shore and breaks

Question 2

What is backwash?

Answer 2

When the water runs out of speed, it stops and flows back down the beach into the sea

Question 3

What are constructive waves?

Answer 3

• Waves that have a strong swash that pushes sand and stones onto the shore and a weak backwash
• typically occur on calm days, contributing to beach buildup.

Question 4

What are destructive waves?

Answer 4

• Waves that erode the coastline, are strong and tall, plunge deeply onto the shore, and have a powerful backwash (weak swash)
• can drag stones, sand, and even people back into the water.

Question 5

List three factors that determine the height and strength of waves.

Answer 5

• The length of time the wind is blowing for
• The fetch (distance the wave has travelled before it reaches land)
• The strength of the wind

Question 6

Name the 5 processes of coastal erosion

Answer 6

• hydraulic action
• abrasion
• solution
• attrition
• Air compression

Question 7

Hydraulic action

Answer 7

Force of fast flowing water

Question 8

Abrasion

Answer 8

River’s load hitting the sea bed

Question 9

Solution

Answer 9

Rocks dissolving

Question 10

Attrition

Answer 10

Stones collide & roll

Question 11

Air compression

Answer 11

Constant explosive pressure and release of air from waves hitting land (rocks)

Question 12

Name 5 features of sea erosion

Answer 12

Cave, arch, stack, stump, blowhole

Question 13

How does a sea cave form

Answer 13

When a notch is eroded in the rock at the base of a cliff, overtime, the notch develops into a sea cave

Question 14

How does a blowhole form

Answer 14

When air gets compressed by waves, when the wave retreats, it shatters the rock and makes a hole

Question 15

How does a sea arch form

Answer 15

When erosion of the sea cave continues and it eventually cuts through to the other side of the headland

Question 16

How does a sea stack form

Answer 16

when the roof of a sea arch collapses, it is isolated from the headland

Question 17

How does a sea stump form

Answer 17

when a sea stack is eroded by the sea

Question 18

What is a blowhole

Answer 18

a shaft that goes through the roof of a sea cave, sea water sprays out of the hole during stormy weather

Question 19

Name 4 features of sea deposition

Answer 19

Sand spit, sand bar, lagoon, tombolo

Question 20

What are 3 processes of sea deposition

Answer 20

longshore drift, deposition, constructive waves (eg. Howth, Co.Dublin)

Question 21

Sand spit

Answer 21

a narrow ridge of sand or shingle, one end juts out into the sea while the other is connected to land

Question 22

Sand bar

Answer 22

a narrow ridge of sand or shingle which seals off the mouth of the bay

Question 23

Lagoon

Answer 23

a small lake formed behind a sand bar

Question 24

Tombolo

Answer 24

a narrow ridge of sand or shingle which joins an offshore island to the mainland

Question 25

How is a sand spit formed

Answer 25

When material carried by longshore drift is deposited, it builds up gradually and forms a sand spit

Question 26

How is a sand bar formed

Answer 26

When a sand spit grows in length and completely seals off a bay

Question 27

How is a tombolo formed

Answer 27

When a sand spit grows in length and reaches a nearby island

Question 28

Name 2 positive effects fo the sea

Answer 28

Transport, recreation activities

Question 29

Name 2 negative effects of the sea

Answer 29

Oil spilling, littering in the ocean