Tephra fall simulations for Apoyeque volcano using TephraProb software.

Abstract

This work develops an analysis of volcanic hazard due to tephra fall in the Apoyeque volcano through analysis of eruptive scenarios and numerical modeling. The results indicate a preferential dispersion towards the NE-SW, determined by the prevailing directions of the winds in the volcanic zone with longer duration eruptions that increase the probability of tephra accumulation in proximal areas and reduce it in distal areas. A simple qualitative analysis suggests that the municipalities of Mateare and Ciudad Sandino are the most likely to be impacted. For the hazard assessment, an analysis of volcanic geology, compilation of historical eruptive activity and review of deposits (bibliography) was made; analyzing the characteristics of tephra fall and dispersion in order to evaluate possible scenarios and danger zones. To carry out this work, the TephraProb model (Biass et al., 2016a) was used, a toolbox that is based on the Tephra2 numerical model (Bonadonna et al., 2005), entering eruptive parameters of scenarios to be modeled, to then obtain results of Probabilistic accumulation of tephra of 10 kg/m2, 50 kg/m2, 100 kg/m2 and 500 kg/m2 presented on maps with probability isolines. The development of this methodology and the results presented in this work are a resource for the implementation of volcanic emergency plans in the study area.