Slow deformation waves in an elastoplastic medium with faults

Abstract

Slow deformation waves are excited mainly by natural processes in the Earth’s crust and lithosphere and are manifested in changes in the seismic regime and geophysical fields. There are two main types of slow deformation waves: inter-fault and intra-fault. The principal difference in the nature of the propagation of these zones is that in the case of transmission of deformation excitation from fault to fault (inter-fault wave) the speed value is in the range from 20 km/year to 30 km/year or more. If the excitation of processes occurs within a single fault zone (intra-fault wave) the speed varies from 10 km/year to 4 km/year or less. Structural maps of the model medium with faults were used to study the generation and propagation of inter-fault slow deformation waves. A mathematical model proposed by P. V. Makarov was used to perform test calculations for the generation and propagation of slow deformation waves in nonlinear elastic-plastic media. The features of the propagation of deformation waves are investigated for different fault positions in the calculation region. It is shown that the propagating fronts of slow perturbations in the medium have different shapes depending on the location of the faults in the calculation regions. The zigzag nature of the wave front is revealed in a medium with faults in the center. When fault ends are located near the boundary of the calculation region, they have a quasi planar shape.