Volcanic activity happens across the surface of the globe therefore bringing hazards to every affected area. A hazard is any source of potential damage, harm or adverse health effects. A volcanic hazard is any threat to life and infrastructure due to volcanic activity and related situations such as a landslide near the volcano. Volcanoes can be very dangerous and therefore present many hazards towards both people and land. They have the ability to kill and destroy, ruining livelihoods and destroying large land masses. The extent of the hazard can differ depending on how prepared an area is for an eruption and how much planning has gone behind minimising the impact. There are many different types of volcanic hazard and each can have different impacts on the economy, society and environment in a region. It is extremely important that disaster reduction measures, such as early warning systems and land use planning, are reinforced to try to reduce these impacts. There are three main stages to consider when managing a volcano. The first stage is planning and preparing before the eruption, during its critical period (as it is erupting) and evacuation.
Before an eruption there are number of ways to prepare and plan for a volcanic hazard. The most obvious is the prediction of volcanic eruptions, for example, seismic shock waves were used to predict an eruption 48 hours in advance, which resulted in the evacuation of the local population around Popocatepetl, Mexico, in 2000. The development of methods to predict volcanic eruptions is particularly important to provide information for the evacuation of populated regions with around half a billion people now living in the danger zones surrounding the world’s volcanoes. A prediction is a precise statement including the area that will erupt, when it will erupt and the hazards that may arise from the specific eruption. It is easy to