The restless earth - Monserrat volcanic eruption (case study)

Question 1

in what year did Monserrat volcano erupt?

Answer 1

1995

Question 2

what type of volcano is Monserrat?

Answer 2

composite cone volcano

Question 3

what type of island is Monserrat situated on?

Answer 3

a Caribbean island

Question 4

how long has it been dormant for?

Answer 4

350 years

Question 5

when was the most damaging eruption after 1995?

Answer 5

1997

Question 6

what plate margin does Monserrat lie on?

Answer 6

a destructive-subduction plate margin where two oceanic plates are moving together due to convection currents in the molten mantle below

Question 7

what are the two oceanic plates called?

Answer 7

Atlantic plate and the Caribbean plate

Question 8

what happens to the subducted plate?

Answer 8

is melts as the temperature increases and mixes with sea water to form viscous, acidic magma

Question 9

what is the final stage of the eruption?

Answer 9

pressure in the mantle causes the magma to rise upwards and escape through a vent in the rock-eruptions

Question 10

negative primary effects - in 1996 how many tonnes of ash fell on the island?

Answer 10

500 000 tonnes

Question 11

negative primary effects - how long was Plymouth (the capital) plunged into darkness for?

Answer 11

15 minutes

Question 12

negative primary effects - what did the weight of the ash do?

Answer 12

buckled roofs, destroyed crops, buried whole settlements and destroyed coral reefs

Question 13

negative primary effects - what lung disease did it cause?

Answer 13

silicosis

Question 14

negative primary effects - in 2010 what did happened because of an ash cloud?

Answer 14

grounded local flights

Question 15

negative primary effects - what then happened in 1997?

Answer 15

a series of pyroclastic flows consisting of rocks and hot poisonous gases (700 C) as the volcano’s lava domes collapsed

Question 16

negative primary effects - how many people did the pyroclastic flows kill in 1997?

Answer 16

19 people in the area

Question 17

negative primary effects - what happened in 2003?

Answer 17

boulders of 1m in diameter (volcanic bombs) were hurled up to 2Km from the volcano due to the force of the blasts

Question 18

negative secondary effects - what happened in 1998?

Answer 18

heavy rain associated with Hurricane George produced huge lahars (mudflows)

Question 19

negative secondary effects - what did these mudflows cause?

Answer 19

completely buried Plymouth and its infrastructure and it has remained abandoned ever since

Question 20

negative secondary effects - what has happened to the population?

Answer 20

it has declined from 12 000 people before the eruptions to 5000 today - now a bigger proportion of the population is elderly

Question 21

negative secondary effects - what percentage of its GDP did Montserrat’s tourism rely on?

Answer 21

25%

Question 22

negative secondary effects - what percentage reduction of tourists happened after the 1997 eruption?

Answer 22

50%

Question 23

negative secondary effects - because the airport was destroyed what has happened?

Answer 23

only small 20-seat planes can land

Question 24

positive impacts - what has happened to the tourist side of things?

Answer 24

it is now a major tourist attraction so helps to generate jobs and money for the economy

Question 25

positive impacts - what does the Monserrat tourist board now offer?

Answer 25

‘volcano-adventure holidays’

Question 26

positive impacts - what has the weathered ash done for the soil?

Answer 26

forms fertile soil which benefits farmers as crops can be grown

Question 27

positive impacts - how has it benefited scientists?

Answer 27

scientific monitoring of the volcano helped scientists to improve their prediction skills and save lives elsewhere

Question 28

Immediate responses - what did the Monserrat government do?

Answer 28

set up a large exclusion zone around the volcano and evacuated people to the safer land in the North saving many lives

Question 29

Immediate responses - how many people left the island and where did they go?

Answer 29

5000 to nearby islands, the USA or the UK

Question 30

Immediate responses - what did the rescue teams do?

Answer 30

tried to save people trapped in the huge pyroclastic flows but ash grounded their helicopters

Question 31

Immediate responses - what did the British Government build?

Answer 31

temporary schools, hospitals and houses in the North and provided water purification

Question 32

Immediate responses - what was set up in 1996?

Answer 32

The Monserrat Volcano Observatory so the volcano is now one of the most carefully monitored in the world

Question 33

long term responses - what have some of the original residents managed to do?

Answer 33

return to the island from abroad

Question 34

long term responses - what did the British Government provide?

Answer 34

over £200 million of aid to rebuild infrastructure - electricity, roads, a new harbour and airport

Question 35

long term responses - what is the name of the new capital?

Answer 35

Little Bay