About this algorithm: An innovative method for automatic relocation of the focal depth of a local or regional earthquake, especially in the case that only a sparse network with stations located far away from the epicenter is available. For more details please refer to our paper below: Yuan, J., Kao, H., & Yu, J. (2020). Depth-Scanning Algorithm: Accurate, Automatic, and Efficient Determination of Focal Depths for Local and Regional Earthquakes. Journal of Geophysical Research: Solid Earth, 125, e2020JB019430. https://doi.org/10.1029/2020JB019430
Framework:
- Automatic generation of synthetic waveforms for all possible depth phases.
- Match-filtering of all possible depth phases.
- Preliminary determination of the focal depth.
- Final solution based on travel time residuals.
Input:
- Three-component waveforms.
- Velocity model.
Output: Focal depth (median)
Installation requirements (recommend via Anaconda):
- Python 3.6.
- Basic packages: matplotlib, numpy, math, obspy, scipy, pandas.
Data preparation for running DSA:
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Three-component waveforms (SAC) and corresponding response (XML). Waveform data can be one of the groups as follow: BH1/BH2/BHZ, BHE/BHN/BHZ, HH1/HH2/HHZ, HHE/HHN/HHZ, EHE/EHN/EHZ.
SAC header at least should has corrected 'dist' and 'baz'. Please see examples in 'Example1_PAPER-Section3.2', 'Example2_2014-10-07-mw40-Oklahoma', etc.
The response file can be downloaded by using the way like: https://docs.obspy.org/tutorial/code_snippets/stationxml_file_from_scratch.html
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Velocity model (TauP Toolkit format). Example can be seen in 'ak135_Section3.2.nd' in 'Example1_PAPER-Section3.2'
More details see Section 5.1 in TauP manual at https://www.seis.sc.edu/downloads/TauP/taup.pdf
Run test:
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The default example is 'Example1_PAPER-Section3.2'. Run the command like: python DSA_1.0.py
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Running other examples only needs to modify parameters in the 'DSA_SETTINGS.txt'. For example, to run the Oklahoma Mw=4.0 case you can copy all parameters from 'DSA_SETTINGS_Example2.txt' to 'DSA_SETTINGS.txt'
See locating results:
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After running, locating results are in the 'results' folder in the related waveform's directory.
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A demo for plotting comparison of depth solutions is the python script named: 'plot_comparisonFinalSolution_Oklahoma.py'
If you use this software for your research, please cite:
Yuan, J., Kao, H., & Yu, J. (2020). Depth-Scanning Algorithm: Accurate, Automatic, and Efficient Determination of Focal Depths for Local and Regional Earthquakes. Journal of Geophysical Research: Solid Earth, 125, e2020JB019430. https://doi.org/10.1029/2020JB019430
Any questions or advices? Please contact: [email protected] [email protected] [email protected]