Quantifying lava flow hazards in response to effusive eruption

Abstract

The integration of satellite data and mod - eling represents a step toward the next gen - eration of quantitative hazard assessment in response to effusive volcano eruption onset. Satellite-based thermal remote sensing of hotspots related to effusive activity can ef - fectively provide a variety of products suited to timing, locating, and tracking the radiant character of lava flows. Hotspots show the location and occurrence of eruptive events (vents). Discharge rate estimates may indi - cate the current intensity (effusion rate) and potential magnitude (volume). High-spatial- resolution multispectral satellite data can complement field observations for monitor - ing the front position (length) and extension of flows (area). Physics-based models driven, or validated, by satellite-derived parameters are now capable of fast and accurate forecast of lava flow inundation scenarios (hazard). Here, we demonstrate the potential of the in - tegrated application of satellite remote-sens - ing techniques and lava flow models by using a retrospective analysis of the 2004–2005 ef - fusive eruption at Mount Etna in Italy. The lava flow hazard was assessed by using the HOTSAT volcano hotspot detection system, which works with satellite thermal infrared data, and the MAGFLOW lava flow em - placement model, which is able to relate the flow evolution to eruption conditions at the vent. We used HOTSAT to analyze Moder - ate Resolution Imaging Spectroradiometer ( MODIS ) and Spinning Enhanced Visible and InfraRed Imager (SEVIRI) data to out - put hotspot location, lava thermal flux, and effusion rate estimation. This output was used to drive the MAGFLOW simulations of lava flow paths and to continuously update flow simulations. We also show how Landsat-7 Enhanced Thematic Mapper+ (ETM+) and Earth Observing 1 (EO-1) Advanced Land Imager (ALI) images complement the field observations to track the flow front position in time and add valuable data on lava flow advancement with which to validate the numerical simulations. Such integration at last makes timely forecasts of lava flow hazards during effusive crises possible at the great majority of volcanoes for which no monitoring exists