Volcanic Eruption Case Study Soufrière Hills In Montserrat

Question 1

When did the eruption occur?

Answer 1

• 25th June 1997

- Small eruptions started in July 1995

Question 2

What was the size of the eruption?

Answer 2

• Large

- 4-5 million m(cubed) of rocks and gas released

Question 3

What was the death toll?

Answer 3

19 killed

Question 4

What caused the eruption?

Answer 4

• Montserrat on a destructive plate margin (North American plate being forced under the Caribbean plate)
• plate was pushed under by convection currents in mantle, melted to molten rock due to intense heat and friction
• molten rock lighter than surrounding rock so it rises through weak points in crust underneath volcano
• underground magma pool formed, and it gathered until pressure is so great that magma is forced up the main vent to cause an eruption

Question 5

What were the primary impacts?

Answer 5

• large areas covered with volcanic material - Plymouth (capital) buried under 12m of mud and ash
• 20 villages and 2/3 of homes were destroyed by pyroclastic flows
• schools, hospitals, airports and the port were destroyed
• vegetation and farmland destroyed
• 19 people dead, 7 injured

Question 6

What were the secondary impacts?

Answer 6

• fires destroyed many buildings including government offices, police headquarters and town’s central petrol station
• tourists stayed away and businesses were destroyed, which disrupted the economy
• population decline-8000/12000 left since eruptions began in 1995
• volcanic ash improved soil fertility
• tourism is now increasing as people come to see the volcano

Question 7

What were the immediate responses?

Answer 7

• people evacuated from south to safe areas in north
• shelters built for house evacuees
• temporary infrastructure built such as roads and electricity supplies
• UK provided £17m of emergency aid (Montserrat overseas territory of UK)
• local emergency services provided support units to search for and rescue survivors

Question 8

What were the long-term responses?

Answer 8

• risk map created and exclusion zone in place. South of island off limits while volcano is still active
• UK has provided £41m to develop north of island- new docks, airport and houses have been built
• Montserrat Volcano Observatory has been set up to try and predict future eruptions

Question 9

What is a pyroclastic flow?

Answer 9

Fast-moving clouds of super-heated gas and ash