Modelling of crystal deformation in volcanic areas

Abstract

Mogi (1958) used a centre of dilatation in an elastic half-space to model the ground deformation in volcanic areas. We consider four additional axially-symmetric source models, namely, a single force, a dipole, a tensile dislocation and a compensated linear vector dipole (CLVD) and compare the corresponding surface deformation with the surface deformation due to a centre of dilatation. It is found that the vertical displacements due to a dipole, a tensile dislocation and a CLVD decay much faster as compared to the vertical displacement due to a centre dilatation. Moreover, while a centre of dilatation predicts uplift at all epicentral distances, a dispole of a CLVD predicts subsidence after a certain epicentral distance.