Deformation produced by a rectangular dipping fault in a viscoelastic-gravitational layered Earth model .1. Thrust fault - FLTGRV and FLTGRH FORTRAN programs

This is the first article in a series in which we describe theoretical and computational methods for the calculation of viscoelastic-gravitational displacements resulting from rectangular dipping faults into a layered Earth model. We consider a medium composed of one elastic-gravitational layer over a viscoelastic-gravitational half-space, the fault being located entirely in the layer. Calculations of vertical and horizontal displacements as a result of a finite rectangular thrust fault are presented. The FORTRAN 77 programs FLTGRV and FLTGRH used to compute vertical and horizontal displacement, respectively, are described. Finally we present some examples of displacement computations. We consider different dip angles for the fault, and faults that extend partially and totally along the elastic-gravitational layer. The results show that viscoelasticity introduces a long wavelength component into the deformation field that cannot be modeled using purely elastic techniques. It is observed that appropriate consideration must be given to gravity for close held calculations and long periods of time. The model and the programs presented are useful for performing theoretical calculations of displacement in seismic cycles. Copyright (C) 1996 Elsevier Science Ltd.