Session on “Global Disasters: Addressing the Risk Associated with Extreme Geohazards”

Organized by the GHCP.

The global scale spectrum of the volcanic hazard

Maurizio Ripepe, Universita Degli Studi Firenze, Dipartimento di Scienze della Terra, Via La Pira, 4, 50121 Firenze, Italy

Volcanic eruptions inject in the atmosphere millions of cubic meters of ash, gases and debris: their dispersal has impacted in several instances life on Earth, as well as the culture and history of populations living not only in the neighbourhood but also in at several thousands of kilometres of distance from the volcanic source. For this reason volcanic risk cannot be categorized as a factor impacting the society on a local scale: it very often goes beyond political and geographical boundaries and should, therefore, be addressed on a global scale.

The experience of the societal impact of the 2010 eruptions of Eyjafjallajökull, Iceland, rated with Volcanic Explosivity Index (VEI) relatively small and ranging from 3 to 4, highlighted the fragility of the society and infrastructures, in particular when such type of events strike highly populated areas as Europe. The analysis of the effects of such relatively small eruption highlighted as well the paramount need to develop a timely and sound Disaster Risk Reduction plan for low-probability, high-impact volcanic events: such plan should  aim to mitigate damage to persons and goods and assure a robust resilience on local, regional and global scale for various levels of volcanic hazard. Examples of volcanic eruptions and of their societal impact will be discussed.