Lesson 6

Question 1

How do volcanos form?

Answer 1

Where plates interact and friction from shifting plates melts the crust which causes magma to erupt through cracks in plates.

Question 2

What is magma called once it erupts?

Answer 2

lava

Question 3

Basaltic Lava’s temperature?

Answer 3

Hottest

Question 4

Andesitic Lava’s temperature?

Answer 4

Medium

Question 5

Rhyolitic lava’s temperature?

Answer 5

Coolest

Question 6

Basaltic lava’s main material?

Answer 6

50% silica

Question 7

Andesitic lava’s main material?

Answer 7

60% silica

Question 8

Rhyolitic lava’s main material?

Answer 8

70% silica

Question 9

How is basaltic lava formed by?

Answer 9

melting of mantle minerals

Question 10

How is andesitic lava formed by?

Answer 10

subjected ocean plate melts and mixes with sea water

Question 11

How is rhyolitic lava formed by?

Answer 11

melting of liposphere mantle

Question 12

Case study of shield volcano? (3)

Answer 12

Mauna Loa Hawaii
Formed by hotspots
April 1984 last eruption

Question 13

Case study of composite volcano? (4)

Answer 13

Mount st Helens Washington (USA)
last eruption 10 July 2008
IN pacific ring of fire
North American & Pacific plate

Question 14

What volcanic hazards are produced by composite volcanoes?

Answer 14

All.

Question 15

What volcanic hazards are produced by shield volcanoes?

Answer 15

Gases and Lava flow.

Question 16

What are pyroclasric flow?

Answer 16

A cloud of volacnic ash and gas that flows down the steep side of a volcano which has high temperatures and speeds.

Question 17

What are gases hazards?

Answer 17

Carbon dioxide, sulpher dioxide and water are all released by eruptions. When the gases travels up further in the sky. Theses gases can cause climate change and breathing problems.

Question 18

What is a Lahar?

Answer 18

When snow and ice melt and lakes on top of the volcanoes mix with ash to create a concrete like mudflow down the steep sides of volcanoes buring evrything in their path.

Question 19

What is an ash cloud/Tephra?

Answer 19

Violent eruptios can throw enormus clouds of ash into the atmosphere which can bury crops, contaminate water sources and case serious transport and breathing problems as well as contributing towards climate change.

Question 20

What is lava flow?

Answer 20

Most lava travels fast enough to escape from but the tremendous temperatures involved mean fixed items are burnt and destroyed. It is more serous in sheild volcanos as lava flows faster and more viscous.

Question 21

What is the case study for lava flow?

Answer 21

Nyirgongo Volcano 1977

Question 22

What are the characteristcs/effects of Nyirgongo volcano?

Answer 22

Drained in less than an hour
Velocity of lava was 20 - 60km/h
Fowed 9km
Swamped several villages
Killed 400 people

Question 23

What is the case study for ash cloud?

Answer 23

Eyjafallayokull Iceland 2010

Question 24

What are the characteristcs/effects of Eyjafallayokull?

Answer 24

Present across Trans-Atlantic Flight paths
Disrupted aircraft movements to/from Europe
700 people evaculated in Iceland
Main road closed due to por visability

Question 25

What is the case study for gases?

Answer 25

Mount Pinatubo 1991

Question 26

What are the characteristcs/effects of Mount Pinatubo?

Answer 26

20 million tonnes of sulpher dioxide rose 32km in height Cooled earth for 3 years acid rain affected vegitation - contaminated farm land (florine gas)

Question 27

What is the case study for Lahar?

Answer 27

Nevado De Ruiz 1985

Question 28

What are the characteristcs/effects of Nevado De Ruiz?

Answer 28

``` Pyroclastic flows melted 10% of ice Small lahars turned into 6 major river valleys Traveled at 60km/h 2.5 hours travled 100km Killed 23000 people People at homes asleep unable to escape Buildngs swept away ```