Tectonic hazards: Volcanoes

Abstract

Volcanic activity is one of the most exciting natural manifestations of our living planet. Volcanoes generate continuously new lithosphere in expanding plate boundaries and have a key role in recycling it in the subduction plate margins. Volcanoes created the Earth atmosphere (except oxygen component) and gave birth to life in their submarine white smokers. Volcanoes made available the most important elements for human race to survive and evolve: fire, obsidian, sulfur, fertile soils, all precious and base metals and much more. On the other hand, explosive volcanic eruptions are one of the most impressive, violent and destructive natural events and represent a potential threat for hundreds of millions of people. Landscape beauty and soil fertility attracts populations, which settle on volcano flanks, creating, by the conjunction of hazards and population, high risk areas. The population directly at risk from volcanoes nowadays is at least 500 million, representing as much as 7% of mankind. At a larger scale, volcanic emissions (gas and ash) can affect the natural environment on the whole Earth modifying the climate for some years, inducing the so-called “volcanic winters”. (Continued)