Open AccessPersistent uplift of the L azufre volcanic complex ( C entral A ndes): New insights from PCAIM inversion of InSAR time series and GPS data
Author(s) -
Remy D.,
Froger J. L.,
Perfettini H.,
Bonvalot S.,
Gabalda G.,
Albino F.,
Cayol V.,
Legrand D.,
Saint Blanquat M. De
Publication year - 2014
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1002/2014gc005370
Subject(s) - geology , volcano , interferometric synthetic aperture radar , sill , geodesy , seismology , global positioning system , inversion (geology) , crust , magma chamber , principal component analysis , tectonics , magma , geophysics , remote sensing , petrology , synthetic aperture radar , telecommunications , computer science , artificial intelligence
Abstract We reanalyzed the surface displacements observed at the Lazufre volcanic complex in the Southern Andean Central Volcanic Zone using GPS measurements made between 2006 and 2008 and a large InSAR data set. We performed a detailed spatiotemporal analysis of the displacements using a principal component analysis inversion method (PCAIM). The PCAIM reveals a source with no significant changes in shape and dimension and with a remarkably linear strength increase over the whole period of observation (i.e., 2003–2010). Then we used a three‐dimensional mixed boundary element method (MBEM) to invert the first component of surface displacement as obtained from PCAIM. We explored a continuum of geometries from a shallow elliptic crack to a deep massive truncated elliptical cone that could represent a sill or a large magma chamber, respectively. The best models indicate a large flat‐topped source with a roof area between 40 and 670 km 2 and a depth of between 2 and 14 km below ground surface. Lastly, on the basis of the limited data available for the thermomechanical structure of the crust in the Southern Andean Central Volcanic Zone, we consider some possible scenarios to explain the spatial and temporal pattern of displacements at Lazufre.