Chapter 4- Volcanoes

Question 1

Define volcanoes.

Answer 1

Openings or cracks in the earths crust through which magma,ash, cinder and gases erupt or pour

Question 2

How are volcanoes caused?

Answer 2

When plates collide or separate

Question 3

How are volcanoes formed?

Answer 3

• magma seeps up from magma reservoir in mantle through cracks or vents in crust
• pressure builds near surface causing violent eruption that fires ash, cinder and gas into the sky
• lava flows out of crater at top of mountain and down sides
• lava cools and hardens
• layers of lava and ash build up to form cone-shaped volcano with crater on top

Question 4

Define crater.

Answer 4

The mouth of a volcano from which lava, ash, cinder and gases escape

Question 5

Define vent.

Answer 5

The crack in the surface of the ground from which the volcano emerges

Question 6

Define magma chamber.

Answer 6

In mantle

Where magma comes from

Question 7

Define magma.

Answer 7

Molten rock while under ground

Question 8

Define lava.

Answer 8

Molten rock above ground

Question 9

What is a secondary volcano?

Answer 9

A smaller volcano that breaks out on the side of a volcano

Question 10

Define ridge.

Answer 10

Long line of mountains

Question 11

What is the mid Atlantic ridge?

Answer 11

A series of ocean ridges

Question 12

How is the mic Atlantic ridge being formed?

Answer 12

North american and eurasian plates separating.
-> seafloor spreading
As plates separate magma seeps into cracks in crust creating ridges
Some form volcanic island eg Iceland

Question 13

Name a volcano in iceland.

Answer 13

Mt hekla

Question 14

What geothermal action is found in Iceland?

Answer 14

Geysers(throw up jets of hot water and steam)

Geothermal springs

Question 15

What are the advantages of geothermal springs?

Answer 15

Hot water used for washing and central heating
most houses heated by geothermal water
Electricity generated using steam

Question 16

What happened in Iceland in 2010?

Answer 16

Eruptions from a volcano caused huge ash clouds, some rising up to 9km in sky
-> disrupted european air travel

Question 17

What is the pacific ring of fire?

Answer 17

Place where plates meet

Number of active volcanoes in area eg mount st Helen’s US

Question 18

What are the 3 types of volcanoes?

Answer 18

Active
Dormant
Extinct

Question 19

List advantages of volacanoes.

Answer 19

Fertile soils created from lava breakdown
Geothermal springs provides hot water and central heating
New land formed
Tourists visit volcanoes and towns destroyed by them or distinctive landscape created by them

Question 20

List disadvantages of volcanoes

Answer 20

People killed
Towns destroyed
Farmland destroyed 
Lahars cause damage
Ash cloud

Question 21

Name an example or result of volcanic activity in Ireland

Answer 21

Antrim plateau
giants causeway
slemish mountain