More than half of the destructive volcanic eruptions of this century occurred on volcanoes that had had little or no historic activity, and which were therefore deemed to have little or no hazard. The problem is that the characteristic time between a volcano's largest eruptions may well exceed 10,000 years - longer than all of recorded history. This behavior suggests that a statistical approach to assessing volcanic hazard that treats all Holocene volcanoes as potentially hazardous can provide essential information on human vulnerability and mitigation. We propose to construct global probabilistic hazard (likelihood of a damaging physical process occuring) and risk (intersection of hazard with society) maps using rigorous physical and statistical models that are broadly similar to the ones that have proven successful for earthquakes. A key part of this effort will be the construction of "hazard attenuation laws" that relate the probability of an eruption of a given size and place to the intensity of physical repercussions at a given point on the earth's surface. Unlike earthquakes, which have essentially one repercussion (ground shaking), volcanoes have many (ash falls, degassing, explosions, lahars, lava flows, pyroclastic flows, tsunamis, etc.). Each must be treated individually, with every effort made to include known variability due to the specific characteristics of a given volcano. We will then quantify the time-invariant distribution of hazard by producing global maps of hazard. We will also go on to quantify risk to human population, to food production and to critical lifelines (e.g roads, pipelines, etc.) by assessing their fragility to each of the hazards. Some of the relevant population and land use data are available through Columbia's CIESIN and Laboratory of Populations groups, with whom we will have a close collaboration.

Relevance to the Disciplinary Program

This proposal is relevant to the following areas of Solid Earth Science that are important to NASA: topography and surface change, coastal hazards, volcanic hazards, and geological applications of remote sensing.