Testing gas dispersion modelling: A case study at La Soufriere volcano (Guadeloupe, Lesser Antilles)
Authors:Massaro, Silvia Dioguardi, Fabio Sandri, Laura Tamburello, Giancarlo Selva, Jacopo Moune, Severine Jessop, David E. Moretti, Roberto Komorowski, Jean-Christophe Costa, Antonio
Volume:417
DOI:10.1016/j.jvolgeores.2021.107312
Published:2021
Document Type:Article
Abstract:Volcanic gas dispersal can be a serious threat to people living near active volcanoes since it can have short- and long-term effects on human health, and severely damage crops and agricultural land. In recent decades, reliable computational models have significantly advanced, and now they may represent a valuable tool to make quantitative and testable predictions, supporting gas dispersal forecasting and hazard assessments for public safety. Before applying a specific modelling tool into hazard quantification, its calibration and its sensitivity to initial and boundary conditions should be carefully tested against available data, in order to produce unbiased hazard quantifications. In this study, we provided a number of prototypical tests aimed to validate the modelling of gas dispersal from a hazard perspective. The tests were carried out at La Soufriere de Guadeloupe volcano, one of the most active gas emitters in the Lesser Antilles. La Soufriere de Guadeloupe has shown quasi-permanent degassing of a low-temperature hydrothermal nature since its last magmatic eruption in 1530 CE, when the current dome was emplaced. We focused on the distribution of CO2 and H2S discharged from the three main present-day fumarolic sources at the summit, using the measurements of continuous gas concentrations collected in the period March-April 2017. We developed a new probabilistic implementation of the Eulerian code DISGAS-2.0 for passive gas dispersion coupled with the mass-consistent Diagnostic Wind Model, using local wind measurements and atmospheric stability information from a local meteorological station and ERA5 reanalysis data. We found that model outputs were not significantly affected by the type of wind data but rather upon the relative positions of fumaroles and measurement stations. Our results reproduced the statistical variability in daily averages of observed data over the investigated period within acceptable ranges, indicating the potential usefulness of DISGAS-2.0 as a tool for reproducing the observed fumarolic degassing and for quantifying gas hazard at La Soufriere. The adopted testing procedure allows for an aware application of simulation tools for quantifying the hazard, and thus we think that this kind of testing should actually be the first logical step to be taken when applying a simulator to assess (gas) hazard in any other volcanic contexts. (C) 2021 The Authors. Published by Elsevier B.V.
Author Information
Corresponding Author:Massaro, S (通讯作者)，Ist Nazl Geofis & Vulcanol, Sez Bologna, Bologna, Italy.
Reprint Address:Massaro, S (通讯作者)，Ist Nazl Geofis & Vulcanol, Sez Bologna, Bologna, Italy.
Addresses:[Massaro, Silvia; Sandri, Laura; Tamburello, Giancarlo; Selva, Jacopo; Costa, Antonio] Ist Nazl Geofis & Vulcanol, Sez Bologna, Bologna, Italy; [Massaro, Silvia] CNR, Ist Geol Ambientale & Geoingn, Area Ric Roma 1, Sede Montelibretti, Italy; [Dioguardi, Fabio] British Geol Survey, Lyell Ctr, Edinburgh, Midlothian, Scotland; [Moune, Severine; Jessop, David E.; Moretti, Roberto; Komorowski, Jean-Christophe] Univ Paris, Inst Phys Globe Paris, UMR CNRS 7154, Paris, France; [Moune, Severine; Jessop, David E.; Moretti, Roberto] Inst Phys Globe Paris, Observ Volcanol & Sismol Guadeloupe, Gourbeyre, Guadeloupe, France; [Moune, Severine; Jessop, David E.] Univ Clermont Auvergne, CNRS, IRD, OPGC Lab Magmas & Volcans, F-63000 Clermont Ferrand, France
E-mail Addresses:silvia.massaro@ingv.it