2.1 - Volcano Case Study - Soufiere Hills, Montserrat (Paper 1)

Question 1

Key Facts: (5)

Answer 1

• Montserrat is British territory and is located in
  the Carribean
• In July 1995, it became active after being dormant for 400 years
• It erupted explosively on June 25th 1997 and it generated pyroclastic flows
• Montserrat lies on the destructive plate boundary in the middle of the Carribean Plate and the North American Plate
• Soufriere Hills volcano is composite

Question 2

Explain the causes of Soufiere Hills erupting (7)

Answer 2

• Soufiere Hills is a stratovolcano and it is located on the island of Montserrat in the Carribean.
• Montserrat lies on a destructive plate margin meaning the volcano lies at the boundary between an oceanic and continental plate.
• In this case the North American plate acts as the oceanic plate and the Carribean plate acts as the continental plate
• These two plates move to each other but the North American plate subducts due to its greater density
• As the North American plate pressure increases and heat produced by friction melts the crust of the North American plate to form magma.
• This magma is then forced upwards and eventually bursts through the Carribean plate.
• Because Soufiere Hills is a composite volcano, this eruption would be very explosive.

Question 3

Explain the effects the Soufiere Hills eruption had on the people:

Short-term: (3)
Long-term: (3)

Answer 3

SHORT TERM:

• 23 people died and 100 were injured
• 65% of infrastructure was destroyed
• W.H Bramble airport was closed due to unsafety of flying

LONG TERM:

• 99% of the volcanic ash contained harmful chemicals like sulfur.
• 88% of the population evacuated leading to a lack of workers
• Due to housing shortages, rent went up by 70% making it hard for people to live on the island.

Question 4

Explain the effects the Soufiere Hills eruption had on the environment:

Long-term: (3)
Short-term: (3)

Answer 4

SHORT TERM:

• Pyroclastic flows were travelling at around 500km/h, and damaged the environment severely
• 99% of the ash contained harmful chemicals like sulfur
• Animal life became almost impossible because 75% of the island was covered in ash,

LONG TERM:

• The pH of the lake falls below pH of 5.0 the ecosystem is badly effected
• Crops couldn’t grow for a year because the ash covered fields and killed crops. Those who relied on it suffered
• As a result of the eruption, temperatures soared to 41 degrees celcius when the average high temperature is 28 degrees celcious

Question 5

Explain the opportunities presented to people living in Montserrat

Answer 5

• In 2019, 20,000 people visited Soufiere Hills because volcanoes are unique
• 30% of Montserrat’s land is agricultural
• Geothermal power in Montserrat can be generated 24 hours everyday which provides sustainable access to electricity.

Question 6

Explain the short-term responses to the eruption in Montserrat:

Answer 6

• Because Montserrat is ‘British Overseas Territory”, the UK sent $41 million worth of relief equipment
• 5,000 people were evacuated to the North of Montserrat where it was deemed as safe
• The British Royal Navy evacuated 4000 people to the nearby Antigua and Barbuda.

Question 7

Explain the long-term responses to the eruption in Montserrat:

Answer 7

• Residents in Montserrat were offered $2,500 and were also offered to move to the UK
• The UK donated $75 million for reconstruction and long term development
• An exclusion zone was set up in the volcanic region. This extends from the south coast of the island. Pyroclastic activity occured here