IDEAN   23403
INSTITUTO DE ESTUDIOS ANDINOS "DON PABLO GROEBER"
Unidad Ejecutora - UE
artículos
Título:
Deformation of Copahue volcano: Inversion of InSAR data using a genetic algorithm
Autor/es:
MARIA LAURA VELEZ; PABLO EUILLADES; ALBERTO CASELLI; MAURO BLANCO; JOSE MARTÍNEZ DÍAZ
Revista:
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2011 p. 117 - 126
ISSN:
0377-0273
Resumen:
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 CopahueCaviahue 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 kmis 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 volcanichydrothermal
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.