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-gravita tional displacements resulting from rectangular dipping faults into a layered Earth model. We consider a medium composed of one elastic-grav itational layer over a viscoelastic-gravitational half-space, the faul t being located entirely in the layer. Calculations of vertical and ho rizontal displacements as a result of a finite rectangular thrust faul t are presented. The FORTRAN 77 programs FLTGRV and FLTGRH used to com pute vertical and horizontal displacement, respectively, are described . Finally we present some examples of displacement computations. We co nsider different dip angles for the fault, and faults that extend part ially and totally along the elastic-gravitational layer. The results s how that viscoelasticity introduces a long wavelength component into t he deformation field that cannot be modeled using purely elastic techn iques. It is observed that appropriate consideration must be given to gravity for close held calculations and long periods of time. The mode l and the programs presented are useful for performing theoretical cal culations of displacement in seismic cycles. Copyright (C) 1996 Elsevi er Science Ltd.