The global distribution of human population and recent volcanism

This study quantifies the spatial relationship between the global distribution of human population and recent volcanism. Using recently compiled databases of population and Holocene volcanoes, we estimate that almost 9% (455×10⁶ people) of the world's 1990 population lived within 100 km of an historically active volcano and 12% within 100 km of a volcano believed to have been active during the last 10,000 years. The analysis also indicates that average population density generally decreases with distance from these volcanoes (within 200 km). In tropical areas, the elevation and fertile soils associated with volcanic regions can provide incentives for agrarian populations to settle close to potentially active volcanoes. In Southeast Asia and Central America higher population densities lie in closer proximity to volcanoes than in other volcanic regions. In Japan and Chile, population density tends to increase with distance from volcanoes. The current trends of rapid urbanization and sustained population growth in tropical developing countries, combined with agricultural intensification of fertile volcanic terrains could alter the relationship between humans and volcanoes so as to increase both local and global consequences of volcanic eruptions in the future.