The main reason scientists study and monitor volcanoes is so that those living near active volcanoes can be aware of the hazards produced by volcanoes. This awareness will hopefully prevent loss of life and property when an eruption occurs.
When scientists study volcanoes, they map past volcanic deposits and use satellites to look at volcanic features, ash clouds, and gas emissions. They also monitor seismic activity, ground deformation, and geomagnetic, gravimetric, and geoelectrical and thermal changes at a volcano. They study and monitor volcanic gases and monitor the temperature, flow rate, sediment transport, and water level of streams and lakes near the volcano.
By studying volcanic deposits, scientists can produce hazard maps. These maps indicate the types of hazards that can be expected in a given area the next time a volcano erupts. Dating of these volcanic deposits helps determine how often an eruption may occur and the probability of an eruption each year. Monitoring of a volcano over long periods of time will indicate changes in the volcano before it erupts. These changes can help in predicting when an eruption may occur.
It is important that scientists communicate with local government officials and the general public about hazards produced by the volcanoes in their area. This interaction and the development of an emergency plan with established lines of communication will hopefully save lives and encourage better land use planning.