FORTRAN code for calculating synthetic seismograms based on a layered viscoelastic half-space earth model.

Highlights
(1) orthonormal propagator algorithm for numerical stability (more efficient than the reflectivity method)
(2) complex frequency technique for supressing the time-domain aliasing problem
(3) wave-number-domain differential filter technique for suppressing numerical phases
(4) various partial solution options
(5) different shallow structures at source and receiver site
(6) earth flattening transformation

Related codes
MSEIS – for marine seismic application
QSEIS2D - for quasi 2D structure model (only teleseismic applications)

Downloads

https://github.com/pyrocko/fomosto-qseis
https://github.com/pyrocko/fomosto-qseis2d

References
 - Wang, R., (1999), A simple orthonormalization method for stable and efficient computation of Green's functions, Bulletin of the Seismological Society of America, 89(3), 733-741.

FORTRAN code for calculating co-seismic static deformation based on the dislocation theory.

Highlights
(1) incorporating with layered earth structure
(2) incorporating with finite slip models
(3) high numerical efficiency

Downloads
ftp://ftp.gfz-potsdam.de/pub/home/turk/wang/

References
- Wang, R., F. Lorenzo-Martín and F. Roth (2003), Computation of deformation induced by earthquakes in a multi-layered elastic crust - FORTRAN programs EDGRN/EDCMP, Computer and Geosciences, 29(2), 195-207.

FORTRAN code for calculating of co- and post-seismic deformation in multi-layered viscoelastic half-space based on the viscoelastic-gravitational dislocation theory.

Highlights
(1) orthonormal propagator algorithm for numerical stability
(2) finite fault model
(3) gravity effect on deformation
(4) output of complete geophysical observables (displacement, stress/strain, tilt, plate rotation, gravity and geoid changes)

Downloads
https://github.com/pyrocko/fomosto-psgrn-pscmp

References
- Wang, R., F. Lorenzo-Martin and F. Roth (2006), PSGRN/PSCMP - a new code for calculating co- and post-seismic deformation, geoid and gravity changes based on the viscoelastic-gravitational dislocation theory, Computers and Geosciences, 32, 527-541. doi:10.1016/j.cageo.2005.08.006

Code for simulating the diffusion and deformation process induced by pump tests in a layered poroelastic half-space.

Highlights
(1) orthonormal propagator algorithm for numerical stability
(2) fully coupled diffusion and deformation system based on Biot’s poroelasticity theory
(3) wave-number-domain differential filter technique for fast convergence of numerical Hankel transform

Related codes
PEGRN/PECMP – for co- and post-seismic deformation in multi-layered poroelastic half-space

Downloads
ftp://ftp.gfz-potsdam.de/pub/home/turk/wang/

References
 - Wang, R., and H.-J. Kümpel (2003), Poroelasticity: Efficient modelling of strongly coupled, slow deformation processes in a multilayered half-space, Geophysics, 68(2), 705-717.

Code for calculating complete synthetic seismograms of a spherical earth using the normal mode theory.

Highlights
(1) all-in-one code for body waves, surface waves, free oscillations, tsunami for uniform ocean, infrasound waves for a standard atmosphere and static deformation
(2) generating Green’s function database or simulating complete seismograms for any given kinematic source model
(3) hybrid algorithm (numerical integration for low frequency / small harmonic degrees and analytical propagator algorithm for high frequency / large harmonic degrees)
(4) complex frequency technique for supressing the time-domain aliasing problem
(5) differential filter technique for suppressing numerical phases

Related codes
QSSPSTATIC - Co- and post-seismic viscoelastic deformation based on a spherical visco-elastic-gravitational earth model.

Downloads
https://github.com/pyrocko/fomosto-qssp

References
- Wang, R., S. Heimann, Y. Zhang, H. Wang, and T. Dahm (2017). Complete synthetic seismograms based on a spherical self-gravitating Earth model with an atmos-phere-ocean-mantle-core structure. Geophysical Journal International, doi: 10.1093/gji/ggx259.

FORTRAN code for inverting co-seismic surface deformation data (GPS, InSAR, etc.) for fault slip distribution.

Highlights
(1) incorporating with layered crust structure
(2) arbitrarily curved fault geometry
(3) a-priori constraint on the variation range of rake angle
(4) optional smoothing constraint applied to slip or stress-drop
(5) fast optimization algorithm based on the steepest descent method

Downloads
ftp://ftp.gfz-potsdam.de/pub/home/turk/wang/

References
- Wang, L., R. Wang, F. Roth, B. Enescu, S. Hainzl and S. Ergintav (2009), Afterslip and viscoelastic relaxation following the 1999 M 7.4 Izmit earthquake from GPS measurements, Geophysical Journal International, 178(3), 1220-1237.
 - Wang, R., B. Schurr, C. Milkereit, Zh. Shao and M. Jin (2011). An improved automatic scheme for empirical baseline correction of digital strong-motion records, Bulletin of the Seismological Society of America, 101(5), 2029–2044, doi: 10.1785/0120110039.
 - Wang, R., S. Parolai, M. Ge, M. Jin, T.R. Walter and J. Zschau (2012). The 2011 Mw 9.0 Tohoku Earthquake: Comparison of GPS and Strong-Motion Data. Bulletin of the Seismological Society of America, doi: 10.1785/0120110264.

die Programme von PYROCKO:
Snuffler  Seismogram browser and workbench
Cake   1D travel-time and ray-path computations
Fomosto Calculate and manage Green’s function databases
Jackseis Waveform archive data manipulation
Grond  Probabilistic source optimization
Kite  InSAR displacement analysis and postprocessing
Talpa Interactive static displacement modelling

link zum Gesamtpaket:  PYROCKO

https://git.pyrocko.org/
https://github.com/pyrocko

MATLAB codes for calculating deformation fields associated with triangular dislocations (TDs) in homogeneous elastic media

Features
The provided codes
(1) allow displacement, strain and stress calculation in both full-space and half-space,
(2) are free of artefact singularities and numerical instabilities,
(3) are independent of the model scale,
(4) are especially useful for simulations incorporating dense meshes of triangular dislocations,
(5) are optimized and well suited for linear and nonlinear geodetic inversion and optimization problems.

Download link
http://volcanodeformation.com/software.html

Reference
Nikkhoo, M., Walter, T. R. (2015): Triangular dislocation: an analytical, artefact-free solution. Geophysical Journal International, 201 (2), 1117-1139. doi:10.1093/gji/ggv035

MATLAB codes for calculating deformation fields associated with rectangular dislocations (RDs), compound dislocation models (CDMs) and generalized point sources of pressure in homogeneous elastic media

Features
The provided codes
(1) allow displacement, strain and stress calculation in both full-space and half-space,
(2) are free of artefact singularities and numerical instabilities,
(3) are independent of the model scale,
(4) address the issue of scale-dependency and numerical artefacts in rectangular dislocation solutions,
(5) are useful for simulating generalized sources of volume change and pressurized point ellipsoidal sources,
(6) are optimized and well suited for linear and nonlinear inversions, especially for volcano deformation modelling.

Download link
http://volcanodeformation.com/software.html

Reference
Nikkhoo, M., Walter, T. R., Lundgren, P. R., Prats-Iraola, P. (2017): Compound dislocation models (CDMs) for volcano deformation analyses. - Geophysical Journal International, 208 (2): 877-894. doi:10.1093/gji/ggw427