MATLAB (mainly) and Python (upcoming) functions for visualization and modeling of shear wave splitting observations:
- Optimized for the output of SplitLab (Wüstefeld et al. (2008)) and StackSplit (Grund (2017)).
- The modeling routine is applicable for the energy minimization method (Silver, Chan (1991)).
- Extended and strongly modified from sws_tools by Michael Grund.
If you make use of this material, please acknowledge the relating publications in which framework these functions were implemented:
Peer-reviewed journal articles
- Fröhlich Y, Grund M, Ritter J R R (2024). Lateral and vertical variations of seismic anisotropy in the lithosphere-asthenosphere system underneath Central Europe from long-term splitting measurements. Geophysical Journal International, 239(1):112-135. https://doi.org/10.1093/gji/ggae245.
- Ritter J R R, Fröhlich Y, Sanz Alonso Y, Grund M (2022). Short-scale laterally varying SK(K)S shear wave splitting at BFO, Germany – implications for the determination of anisotropic structures. Journal of Seismology, 26:1137-1156. https://doi.org/10.1007/s10950-022-10112-w, correction https://doi.org/10.1007/s10950-023-10136-w.
Doctoral studies
- Fröhlich Y (2025). Shear wave splitting analysis of long-term data: Anisotropy studies in the Upper Rhine Graben area, Central Europe. Dissertation, Karlsruhe Institute of Technology, Geophysical Institute. https://doi.org/10.5445/IR/1000183786.
Presentation
- Fröhlich Y, Ritter J R R (2024). Vertical and Small-scale Lateral Varying Seismic Anisotropy in the Upper Mantle Underneath the Upper Rhine Graben, Central Europe. Annual Meeting of the American Geophysical Union, Washington D.C.. Division Session Exploring Innovations and New Directions in Seismic Anisotropy and Attenuation: Observations, Models, and Experiments I Oral, DI21A-02. Abstract ID 1578275. https://dx.doi.org/10.5281/zenodo.14510993.
Example figures: Generated with the provided test data
Tested with: R2022a, R2021a,b under Linux and Windows
- MATLAB: Forward calculation
- Deep Learning Toolbox
- Mapping Toolbox
- MATLAB Seismic Anisotropy Toolkit (MSAT) (Walker, Wookey (2012))
- Data: Shear wave splitting observations
- Output *.txt files (nulls, splits) of SplitLab version 1.5.0 (Wüstefeld et al. (2008)) or 1.2.1 (Porritt 2014)
- Output *.mat structure and *.txt files (STACK, SIMW) of StackSplit (Grund (2017))
- Colormaps (optional): Color-coding of the fast polarization direction and the root mean square error
- MatPlotLib Perceptually Uniform Colormaps
version v2.1.3, MATLAB File Exchange, last access 2022 June 26 - crameri perceptually uniform scientific colormaps
version v1.09, MATLAB File Exchange, last access 2023 April 10; based on Crameri (2021) - cmocean perceptually-uniform colormaps
version v2.02, MATLAB File Exchange, last access 2022 June 18; based on Thyng et al. (2016)
- MatPlotLib Perceptually Uniform Colormaps
| Release | Zenodo DOI | Publication | RADAR4KIT dataset |
|---|---|---|---|
| dev | |||
| v2.0 | Fröhlich et al. (2024) | https://dx.doi.org/10.35097/685 | |
| v1.0 |  |
Ritter et al. (2022) | https://dx.doi.org/10.35097/684 |
For details of the individual releases as well as for changes and differences compared to sws_tools by Michael Grund see the changelog.
- Modeling of multi-event analysis: Only using either STACK or SIMW results is supported
- Model parameter distribution for T1: Under development, not fully tested
- Synthetic stereoplot for T1 and H2: Backazimuths of predicted nulls are partly wrong
- Synthetic stereoplot for T1: Gray arrow is partly not exactly placed in the center
For bug reports, suggestions or recommendations feel free to open an issue or submit a pull request directly here on GitHub.
| Software | Language | Description | Author |
|---|---|---|---|
| MSAT | MATLAB | Toolkit for the analysis of elastic and seismic anisotropy | A M Walker, J Wookey |
| PyDRex | Python | Simulate crystallographic preferred orientation evolution in polycrystals | L Bilton, T Duvernay |
| PyRaysum | Python | Software for modeling ray-theoretical body-wave propagation | W Bloch, P Audet |
- Bowman J R, Ando M (1987). Shear-wave splitting in the upper-mantle wedge above the Tonga subduction zone. Geophysical Journal International, 88(1):25-41. https://doi.org/10.1111/j.1365-246X.1987.tb01367.x.
- Crameri F (2021). Scientific colour maps, version 7.0.1. Zenodo. https://www.fabiocrameri.ch/colourmaps.php. https://zenodo.org/record/5501399.
- Grund M (2017). StackSplit - a plugin for multi-event shear wave splitting analyses in SplitLab. Computers & Geosciences, 105:43-50. https://doi.org/10.1016/j.cageo.2017.04.015.
- Porritt R W (2014). SplitLab version 1.2.1. available at https://robporritt.wordpress.com/software/.
- Restivo A, Helffrich G (1999). Teleseismic shear wave splitting measurements in noisy environments. Geophysical Journal International, 137:821-830. https://doi.org/10.1046/j.1365-246x.1999.00845.x.
- Roy C, Winter A, Ritter J R R, Schweitzer J (2017). On the improvement of SKS splitting measurements by the Simultaneous Inversion of Multiple Waveforms (SIMW). Geophysical Journal International, 208:1508-1523. https://doi.org/10.1093/gji/ggw470.
- Silver P G, Chan W W (1991). Shear wave splitting and subcontinental mantle deformation. Journal of Geophysical Research, 96(B10):16429-16454. https://doi.org/10.1029/91JB00899.
- Thyng K M, Greene C A, Hetland R D, Zimmerle H M, DiMarco S F (2016). True colors of oceanography: Guidelines for effective and accurate colormap selection. Oceanography, 29(3)9-13. https://dx.doi.org/10.5670/oceanog.2016.66.
- Walker A M, Wookey J (2012). MSAT — A new toolkit for the analysis of elastic and seismic anisotropy. Computer & Geosciences, 49:81-90. https://doi.org/10.1016/j.cageo.2012.05.031. available at https://www1.gly.bris.ac.uk/MSAT/, https://github.com/andreww/MSAT.
- Wolfe C J, Silver P G (1998). Seismic anisotropy of oceanic upper mantle: Shear wave splitting methodologies and observations. Journal of Geophysical Research: Solid Earth, 103(B1):749-771. https://doi.org/10.1029/97JB02023.
- Wüstefeld A, Bokelmann G, Zaroli C, Barruol G (2008). SplitLab: A shear-wave splitting environment in Matlab. Computers & Geosciences, 34(5):515-528. https://doi.org/10.1016/j.cageo.2007.08.002.
The presented research and YF received support from various sources:
- Graduate Funding from the German States (scholarship)
- NSF grant EAR-1948602 (travel support for AGU24)
- DFG grant RI1133/14-1 within the DFG Priority Program 2404 DeepDyn (research assistant)