Was the eruption predicted ?
The scientists at the Montserrat Volcano Observatory (MVO) play a key role monitoring the developments of the Soufrière Hills Volcano. Despite sophisticated monitoring equipment it still remains very difficult to pinpoint exactly when an eruption will happen. From an early stage the MVO predicted increased volcanic activity and the dangers associated with them. Continuous monitoring of the volcano is vital in the scientist role to obtain accurate data. The Soufrière Hills Volcano was monitored using a number of different methods.
Before an eruption, magma moves into the area beneath the volcano and collects in a magma chamber, or reservoir. The movement of magma produces small earthquakes and vibrations. This is called seismic activity. A seismometer is an instrument that measures ground vibrations caused by earthquakes. In Montserrat 14 seismometers close to the volcano record ground movements which are converted to radio signals. These signals are transmitted to computers that record the earthquakes 24 hours a day.
As magma nears the surface its pressure decreases and gases escapes. Sulphur dioxide is one of the main volcanic gases. Gases released by most volcanoes are difficult to sample and measure on a regular basis, especially when a volcano becomes active. At the Soufrière Hills Volcano gas emissions are measured using a spectrometer. A spectrometer uses the sun as source of infrared radiation. This means the spectrometer looks at the sun through the volcanic plume. From this it can measure the amount of gas in the atmosphere.
Pressure from rising magma deforms the volcano. The ground can change shape by rising up, subsiding, tilting, or forming bulges. The newest and most accurate system of measuring ground deformation is the Global Positioning System (GPS). This involves using a number of satellites and radio waves. A receiver is set up close to the volcano then data can be transmitted between satellites orbiting the earth and the receiver. Data is obtained in just a few minutes and is extremely accurate. Another method involves measuring tiny changes in the slope angle or "tilt" of the ground with tiltmeters. Five electronic tiltmeters record ground deformation around the flanks of the Soufrière Hills Volcano.
Geological observations and measurements help scientists at the MVO improve their knowledge of the volcano. The recording of data and observation is extremely important as scientists from all over the world visit the observatory and try to make sense of the recorded results. Since the beginning of the eruption the MVO has recorded data. This data assists the government on what action to take to ensure the safety of the people of Montserrat.
What actions were taken before, during and after the eruption ?
Before 25 June 1997 the British Government began to fund a temporary infrastructure in the north of the island including a jetty, roads, water and electricity. This development was extremely slow and the housing conditions were of a poorer quality than the local population were used to. During this time the British and Montserrat Governments both adopted a 'wait and see' approach because the volcano had not been particularly active up until this point. More significantly, if the developments in the north of the island remained temporary less funding would have to be given.
Actions taken by the MVO on 25 June 1997 helped to save lives. Continuous monitoring of the volcano enabled the scientists to predict that an eruption would be likely that day and evacuations of controlled areas within the exclusion zone were conducted successfully. Search and rescue teams were deployed quickly, enabling survivors to be picked up by helicopter or vehicle. Specialist medical support ensured treatment for burns victims.
After 25 June 1997 the volcano went through a period of violent eruption. The Exclusion Zone was extended and greater pressure was put on the remaining facilities in the North. The airport and the Plymouth port were closed and eventually destroyed by pyroclastic flows. The British Government finally agreed to fund a crisis programme of action (£56 million) and to support development in the north of the island. Other Caribbean islands, organisations such as CDERA and the Red Cross also gave aid to Montserrat.
As recently as March 2003 the Soufrière Hills Volcano is still active and shows signs of slighlty increased activity. Lava dome growth, pyroclastic flows and rockfalls are still being observed. As long as the volcano is active there can be no development or return to the south of the island.
The eruption of the Soufrière Hills Volcano began on 18 July 1995. Nearly a year later, the volcano forced the islanders to evacuate the capital, Plymouth, situated only 4 km from the volcano. The government set up a risk map to ensure people were a safe distance away from the dangerous pyroclastic flows that had so far destroyed areas to the south and east of the volcano. Initially, the zones were given a letter code. Moving from zones G to A represents an increased risk. The status of each zone was dependent on volcanic activity at that time. Unfortunately this did not prevent disaster on 25 June 1997.
Here's what a star student thought of this essay
Quality of writing
The spelling and grammar and punctuation were fine. I found one mistake of "slighlty" instead of "slightly". This shows the lack of proof reading which is essential in limiting such silly mistakes. However, one slip up like this would not affect the mark greatly, although the impression on the examiner is not very good. The technical terms were appropriately used and well integrated into the answer. The student does not present their work in one long essay format which is interesting. However, there is no 'right' way to present geography work like this and using subtitles is a sensible way as well as presenting it as one long extended essay.
Level of analysis
The level of analysis is excellent. The student supports each point well with evidence and evaluated the evidence they found. Perhaps a bibliography would have been good to show the sources used for this piece of work. The appropriate conclusion was made using well supported material. I would suggest that any diagrams / pictures and so on be sourced accordingly as well to avoid infringing copyright or being accused of plagiarism. The response was coherent and well developed through the use of strong and well selected evidence.
Response to question
The student demonstrates a high level of understanding to the eruption right from the start as their introduction shows a clear knowledge towards the tectonic plate theory which caused the eruption. The answer is well supported by evidence and each point the student makes is clearly supported. This creates a convincing and fluent piece of written work which would score the student very high marks. Their response is very clear as the student has laid out the work under subtitles which helps guide the examiner through the work.