Subduction zone earthquake cycles/sequences

Compute the response of a subduction zone to periodic events or sequences imposed at specified times in a kinematically and dynamically consistent manner.

The geometry is a two-dimensional subduction zone setup (plane strain - ESPM), and the deforming areas of the mantle have been collapsed onto a zero-width shear zone (a fault) to ease computations
The stress calculations are done in using the eigen-strain representation of elastic response to equivalent body-forces. These stress interactions are facilitated by a kernel representation $(K)$ of linear elasticity i.e., the boundary element/integral method $\left(\dot{\tau} = K(v - v^{\infty})\right)$
Impose periodic/aperiodic earthquakes within the coseismic domain
The domain where stress is computed and evolves is explicitly outside the coseismic domain
The post- and inter-seismic domain is parameterized by rate-dependent friction $\left(\tau = \sigma_n\left(f_0 + (a-b)*\log(\frac{v}{v_0})\right)\right)$ and by power-law viscous flow $\left(v = A\tau^n\right)$

To run the code, use the MAIN_simpleSZ_imposedcycles.m file. Change the fault $(a,b,\sigma_n)$ and viscous shear zone $(A^{-1},n)$ properties accordingly - they can be a spatially fixed value or they vary arbitrarily in space. In the latter case, provide them as a vector with the same dimensions as the discretized boudnary elements. Currently the code works for power-laws only for the upper interface in the ESPM, and odd powers for the lower interface.

For issues, questions and if you want to discuss please write to me rmallick@caltech.edu

More information about this method and possible uses are shown in a recent AGU 2022 poster Tobias Köhne, Rishav Mallick, Mark Simons. Investigating the Potential of Multisequence Displacement Timeseries for Fault Rheology Estimation. Authorea. December 05, 2022. DOI: 10.1002/essoar.10513000.1

mallickrishg/viscofricsubduction2d_evo

Subduction zone earthquake cycles/sequences