A probabilistic hazard mapping tool for the Long Valley volcanic region (CA, USA)

Abstract

Probabilistic hazard maps are used to graphically represent forecasts of potentially hazardous volcanic processes associated with an eruption. The construction of a probabilistic hazard map requires the characterization of all possible scenarios (aleatoric variability) that might lead to an event of interest. These scenarios then must be “fed in” to a physical model of the geophyiscal process which are typically computationally expensive to exercise. We present a hazard-mapping tool for the Long Valley region of California. This tool utilizes statistical surrogates of the physical model (in this demonstration, TITAN2D simulations of pyroclastic density currents) to perform rapid hazard assessment. It effectively replaces simulations that take O(min)-O(hours) with function evaluation which take a fraction of a second to exercise. This speed up enables tremendous flexibility in scenario modeling as we can quickly construct and compare probabilistic hazard maps under a variety of scenario models. Furthermore, we can quickly update a probabilistic hazard map as new data or emergent situations arise.