The Sea

Question 1

What does the size of a wave depend on

Answer 1

The wind and the fetch

Question 2

Explain swash

Answer 2

The frothy water that rushes onto the shore after a wave breaks

Question 3

Explain backwash

Answer 3

The water that runs back out to sea from the shore

Question 4

Give the characteristics of a destructive wave

Answer 4

They have a lot of energy and have a strong backwash and weak swash. They erode the coastline

Question 5

Give the characteristics of a constructive wave

Answer 5

They have a strong swash and a weak back wash. It deposits material and builds up the coastline.

Question 6

Explain air compression

Answer 6

The waves trap air in the cracks of rocks and as the waves retreat the trapped air expands and can crack the rock.

Question 7

Explain how a cliff is formed

Answer 7

The waves cut a notch in the rock creating an overhang. The notch then gets deeper and the overhang collapses leaving a wave cut platform. This continues and the coastline retreats inland.
Ex. Cliffs of moher. Co. Clare.

Question 8

Explain how a bays and headlands are formed

Answer 8

A bay is a wide opening in the coastline and a headland is a pice of land jutting out to sea.
Soft rock erodes quickly and hard rock erodes slowly. A bay is formed when soft rock is eroded in between two pieces of hard rock and the headlands are the hard rock.,

Question 9

What is a sea cave and how is it formed

Answer 9

This is a tunnel at the base of a cliff but it doesn’t cut right through the cliff/headland.
The waves erode a weak point into the rock called a cave

Question 10

Explain what and how a sea arch is formed

Answer 10

A sea arch is a passage that runs completely through a headland. T his can happen when a cave is eroded further or two caves meet in the middle to form a complete passage through a headland called a sea arch

Question 11

Explain what and how a sea stack is formed

Answer 11

A sea stack is a pillar of rock standing I. The water near the coast.
When sea arches erode further a sea stack is formed. The roof of the arch collapse forming a pillar of rock isolated from the land.

Question 12

When a sea stack is eroded what is left

Answer 12

A sea stump

Question 13

What is a blowhole

Answer 13

A passage from a cave up to the surface of a cliff top

Question 14

Explain how a blowhole is formed

Answer 14

Compressed air is trapped in the cave by strong waves
The pressure loosens the joints I. The rock above the cliff and eventually this falls into the cliff creating a passage known as a blowhole.

Question 15

Explain the fetch

Answer 15

The length that a wave has to travel

Question 16

Explain a beach

Answer 16

This is built up of sand and shingle deposited by waves between low and high tide levels. Fine material is found on the lower beach and caorse material is found at the upper beach

Question 17

What are sand dunes and how they formed

Answer 17

Sand dunes are hills of sand that pile up on the shore beyond high tide level. Light dry sand is blown inland until trapped by wall or vegetation

Question 18

What is a lagoon and give examples

Answer 18

A lake of water cut off from the sea by a bank of sand or sand bar.
Ex. Lough Gill (Kerry), our lady’s island (Wexford)

Question 19

What are sea walls

Answer 19

Walls made from concrete with a curved top to help deflect the waves back out to sea.

Question 20

What are boulders. In the context of the sea

Answer 20

Large rocks placed at the base of cliffs or I front of sand dunes to prevent erosion by reducing the waves power.