A global, spherical finite-element model for post-seismic deformation using Abaqus

We present a finite-element model of post-seismic solid Earth deformation built in the software package Abaqus (version 2018). The model is global and spherical, includes self-gravitation and is built for the purpose of calculating post-seismic deformation in the far field (>similar to 300 km) of major earthquakes. An earthquake is simulated by prescribing slip on a fault plane in the mesh and the model relaxes under the resulting change in stress. Both linear Maxwell and biviscous (Burgers) rheological models have been implemented and the model can be easily adapted to include different rheological models and lateral variations in Earth structure, a particular advantage over existing models. We benchmark the model against an analytical coseismic solution and an existing open-source post-seismic model code, demonstrating good agreement for all fault geometries tested. Due to the inclusion of self-gravity, the model has the potential for predicting deformation in response to multiple sources of stress change, for example, changing ice thickness in tectonically active regions.

Automated summary

The finite-element model presented in this study, built in the software package Abaqus, is a global and spherical model designed to calculate post-seismic deformation in the far field of major earthquakes. The model includes linear Maxwell and biviscous rheological models, can be easily adapted to different lateral variations in Earth structure, and has been benchmarked against existing models for various fault geometries with good agreement. Due to the inclusion of self-gravity, the model has the potential to predict deformation in response to multiple sources of stress change.