Montserrat case study Flashcards
Where is Montserrat located?
EDC island located in the Caribbean - lesser Antilles island arc
Atlantic plate subducting beneath the Caribbean plate at a convergent plate boundary
Describe the volcanic activity in Montserrat
Chances peak (complex stratovolcano) in Soufrière hills began erupting in 1995 and there has been volcanic activity there for over 16 years Acidic rhyolitic magma - viscous - builds up, pressure builds - violent and explosive eruptions - pyroclastic flows, tephra, vast amounts of ash fall - secondary lahars
Describe levels of development in Montserrat
GDP per capita relatively low - US $8,500 ($35,000 in Italy)
HDI relatively high - 0.821 (0.887 in Italy)
97% literacy levels (99.2% in Italy)
1.2 doctors per 1000 people (4.2 in Italy)
Energy consumption around 22 million kWh per year (300 million in Italy)
Why do people choose to live in Montserrat?
Volcanoes attract tourists, who spend lots of money to visit the country and see the volcanic activity - generates GDP and provides employment in services (tertiary) sector - hotels, gift shops, tours etc.
Mining industry - volcanic activity generates very valuable minerals - e.g volcanic sand in Montserrat, sulfur from fumaroles
Volcanic activity can produce very mineral and nutrient rich soil, which can be of great value to agricultural industries, as well as subsistence farmers
Cultural and sentimental meaning - emotional attachment
+ In Iceland harness geothermal energy - steam heated by magma and used to turn turbines
What are the impacts experienced by people as a result of volcanic activity on Montserrat?
Entire capital city - Plymouth - covered in a thick layer of ash
Thousands lost homes and livelihoods - farmland completely inundated by ash - lack of food to go round at first
11,000 evacuated from southern side of the island
75% of overall island population emigrated by 2002
19 people died
What are the environmental impacts of the Montserrat eruptions?
Delicate coral reef ecosystem surrounding the island destroyed by ash - light blocked out, fall in temperature, change in pH of water, toxic substances
Species such as the mountain chicken frog in serious decline
How has seismology been used in Montserrat as a method of mitigation?
Seismology - using seismometers to collect data on earthquakes and tremors which can be indicative of imminent volcanic activity - seismographs are analysed and compared with seismic data preceding previous eruptions, in order to judge whether an eruption is imminent and action should be taken (e.g. people evacuated) - on Montserrat network of seismometers 6 feet underground used to pinpoint the focus and epicentre of earthquakes
How have GPS and lasers been used as a method of mitigation in Montserrat?
GPS meters that are accurate to the mm can be used to measure ground deformation and the inflation of the volcano - as material and pressure builds up in the volcano, prior to its release in an eruption, its surface can bulge - a clear indicator that an eruption could occur in the near future (e.g. Mt St Helens, USA). Lasers also used to gather ore accurate information on this ground deformation and reduce risk of errors
How is gas spectrometry used in Montserrat as a mitigation method?
Levels of gases such as sulfur dioxide (SO2) can be measured using a technique called gas spectrometry, which uses UV light. Build up of these gases can be an indicator of increased volcanic activity and may precede and eruption - at the present time around 300 tonnes of SO2 being emitted from Montserrat every year
