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. Seismic Activity 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. Gas Emissions 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. Ground Deformation 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 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.