Tephra hazard assessment at Concepci贸n Volcano, Nicaragua

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• 作者：C. Scaini^a ; ^{chiara.scaini@bsc.es} ; A. Folch^a ; M. Navarro^b
• 关键词：Tephra fallout ; Probabilistic hazard maps ; Concepció ; n volcano ; FALL3D model
• 刊名：Journal of Volcanology and Geothermal Research
• 出版年：2012
• 期刊代码：53_03770273
• 类别：ear
• 出版时间：15 March, 2012
• 卷：219-220
• 期：Complete
• 页码：41-51
• 文件大小：2648 K

摘要

Concepci贸n volcano in Ometepe Island, Nicaragua, is a highly active volcano with a rich historical record of explosive eruptions. Tephra fallout from Concepci贸n jeopardizes the surrounding populations, whereas volcanic ash clouds threat aerial navigation at a regional level. The assessment of these hazards is important for territorial planning and adoption of mitigation measures. Here we compute probabilistic hazard maps for Concepci贸n volcano considering three different eruptive scenarios based on past reference events. Previous geological analysis is used to quantify the eruption parameters of the reference events. We account for uncertainties in the definition of the scenarios trough probability density functions. A representative meteorological dataset is created for each scenario by running the WRF-ARW mesoscale meteorological model over a typical meteorological year, defined in terms of wind speed and direction at a given atmospheric height. Tephra transport and deposition under different eruption and wind conditions is modelled using the FALL3D dispersion model. For each scenario, simulations are combined to build probabilistic hazard maps for critical values of tephra load and for threshold values of airborne ash concentration at relevant flight levels. Results are useful to identify the expected impacts for each eruption type and aim at improving the assessment and management of risk in the region.