Abstract
We demonstrate how effects of induced stress may be incorporated in seismic modelling and inversion. Our approach is motivated by the accommodation of pre-stress in global seismology. Induced stress modifies both the equation of motion and the constitutive relationship. The theory predicts that induced pressure linearly affects the unstressed isotropic moduli with a slope determined by their adiabatic pressure derivatives. The induced deviatoric stress produces anisotropic compressional and shear wave speeds; the latter result in shear wave splitting. For forward modelling purposes, we determine the weak form of the equation of motion under induced stress. In the context of the inverse problem, we determine induced stress sensitivity kernels, which may be used for adjoint tomography. The theory is illustrated by considering 2-D propagation of SH waves and related Fréchet derivatives based on a spectral-element method.
| Original language | English |
|---|---|
| Pages (from-to) | 851-867 |
| Number of pages | 17 |
| Journal | Geophysical Journal International |
| Volume | 213 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 1 May 2018 |
Funding
We thank an anonymous reviewer, David Al-Attar, and Editor Martin Mai for helpful comments which helped to improve the manuscript. The open source spectral-element package SPECFEM2D used in this study is freely available via the Computational Infrastructure for Geodynamics (CIG). The research leading to these results has received funding from the European Research Council (ERC) under the European Union’s Seventh Framework Programme (FP/2007-2013) grant agreement number 320639 (iGEO).
Keywords
- Computational seismology
- Elasticity and anelasticity
- Equations of state
- High-pressure behaviour
- Theoretical seismology
- Wave propagation