(b) HOW RECENT VOLCANO OCCURED, THEIR NEGATIVE CONSEQUENCES ON PEOPLE AND THE ENVIRONMENT AND MEASURES TO MITIGATE/MANAGE THEIR IMPACTS Volcanoes as hazards Most volcanoes occur along plate boundaries. Many volcanic eruptions occur in unpopulated locations (e.g. submarine eruptions at mid ocean ridges) and so are not a hazard to people. Although many volcanic eruptions are spectacular and attract much media attention, the hazard impact caused by a volcano is not as great as that of an earthquake. There are around 1,500 active volcanoes in the world. However 500 of these have erupted in historical time. Nearly 75% of these active volcanoes are located around the Pacific 'Ring of Fire'.​