Three-dimensional indirect boundary element method for deformation and gravity changes in volcanic areas: Application to Teide volcano (Tenerife, Canary Islands)

摘要

Most deformation models of volcanoes assume that the Earth is a linear, elastic, isotropic and homogeneous half-space, although some volcanic areas are associated with significant relief. We investigate the effects of topography on surface deformation and gravity changes caused by a magma intrusion in the Earth's crust. A three-dimensional (3-D) indirect boundary element method (IBEM) that incorporates realistic topographic features is developed in order to perform this analysis. Our results show that the topography alters both the magnitude and pattern of the deformation and gravity signal. As an example of realistic topography, we consider a spherical source of dilatation located at 4 km depth below Teide volcano summit (Tenerife, Canary Islands) in order to simulate the deformation and gravity changes that could be observed at Tenerife if a hypothetical intrusion occurred in the volcanic system. This approach gives a picture of the 3-D topographic effect at Teide that can provide insight in order to improve the geodetic monitoring of the volcano.