Volcanic eruption in an LEDC: Soufriere Hills, Montserrat

Background

- When: 1995 – 1998

- Where: South of Montserrat, Carribean

Causes

- Destructive (N. American subducted 2.2cm/year + Caribbean Plate)

- Strato volcano: andesite

Primary Hazards

- Pyroclastic explosion – 400c at 100m/h

- Ash plume

- CO2 + sulphur emitted

- Lapilli 

Secondary Hazards

- Gas + steam

- Lahars

- Earthquakes 

- Fires

Warning Sings

- 1992/4 – earthquake swarms detected

- Nov 1995 – swelling of volcano dome

- pH of rain changed due to sulphur dioxide 

Monitoring (all done by US)

- Seismograph network – earthquake

- Tilt meters – ground swelling/deflating

- COSPEC – gas emissions especially…