Jiménez, D., Becerril, L., Bartolini, S., Escobar, D., & Martí, J. (2020). Making a qualitative volcanic-hazards map by combining simulated scenarios: An example for San Miguel Volcano (El Salvador). Journal of Volcanology and Geothermal Research, 395, 106837. https://doi.org/https://doi.org/10.1016/j.jvolgeores.2020.106837
Abstract
San Miguel volcano (or Chaparrastique), one of El Salvador’s most active volcanoes, has erupted 28 times in the past 431 years (historical period). The majority of historical eruptions have been Strombolian (VEI 1–2) that have occurred from the central vent and have generated ashfall and ballistics, but some of them (8) have been effusive flank eruptions, mainly producing lava flows of basaltic and basaltic-andesite composition. Secondary lahars generated by remobilization of the young tephra are also common at San Miguel volcano. Using the information for these historical as well as prehistoric eruptions and applying probabilistic tools designed for volcanic-hazards assessment, we simulated: (1) the five most likely scenarios (ashfall scenarios, local-moderate extent, and VEI 1–2); (2) other probable scenarios related to lava flows, based on the historical record of the volcano; (3) other possible scenarios related to pyroclastic density currents (PDCs) with similar characteristics to those that occurred during its eruptive history; and (4) the most hazardous scenarios (ashfall, lava flow, PDC) that have been identified from its prehistoric geological record. Finally, we construct a qualitative integrated volcanic hazard map through the combination of the simulated scenarios. This study was developed with the aim of improving the existing volcanic-emergency plan. It should serve to improve the collaboration and coordination between scientists, the national observatory (OA-MARN), and the civil protection agency of San Miguel municipality, and will help to strength this cooperation to respond effectively to future volcanic crises.