Deformation of Copahue volcano: Inversion of InSAR data using a genetic algorithm

The Copahue volcano is one of the most active volcanoes in Argentina with eruptions having been reported as recently as 1992, 1995 and 2000. A deformation analysis using the Differential Synthetic Aperture Radar technique (DInSAR) was performed on Copahue-Caviahue Volcanic Complex (CCVC) from Envisa...

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Detalhes bibliográficos
Autores: Velez, Maria Laura, Euillades, Pablo Andrés, Caselli, Alberto Tomás, Blanco, Mauro Hugo, Díaz, Jose Martínez
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2011
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositório:CONICET Digital (CONICET)
Idioma:inglês
OAI Identifier:oai:ri.conicet.gov.ar:11336/68449
Acesso em linha:http://hdl.handle.net/11336/68449
Access Level:Acceso aberto
Palavra-chave:Copahue Volcano
Deformation Source
Genetic Algorithm
Sbas-Dinsar
Subsidence
Volcanic-Hydrothermal System
https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
Descrição
Resumo:The Copahue volcano is one of the most active volcanoes in Argentina with eruptions having been reported as recently as 1992, 1995 and 2000. A deformation analysis using the Differential Synthetic Aperture Radar technique (DInSAR) was performed on Copahue-Caviahue Volcanic Complex (CCVC) from Envisat radar images between 2002 and 2007. A deformation rate of approximately 2 cm/yr was calculated, located mostly on the north-eastern flank of Copahue volcano, and assumed to be constant during the period of the interferograms. The geometry of the source responsible for the deformation was evaluated from an inversion of the mean velocity deformation measurements using two different models based on pressure sources embedded in an elastic homogeneous half-space. A genetic algorithm was applied as an optimization tool to find the best fit source. Results from inverse modelling indicate that a source located beneath the volcano edifice at a mean depth of 4 km is producing a volume change of approximately 0.0015 km/yr. This source was analysed considering the available studies of the area, and a conceptual model of the volcanic-hydrothermal system was designed. The source of deformation is related to a depressurisation of the system that results from the release of magmatic fluids across the boundary between the brittle and plastic domains. These leakages are considered to be responsible for the weak phreatic eruptions recently registered at the Copahue volcano. © 2011 Elsevier B.V.