Locate one seismic event relative to another using broadband f-k analysis on cross-correlation trace waveforms
Release v1.0.0 is permanently stored on Zenodo with DOI 10.5281/zenodo.18213676
https://doi.org/10.5281/zenodo.18213676
The folder cc_trace_files contains cross-correlation traces in SAC format generated by the program ccdtest (see https://github.com/stevenjgibbons/ccdtest)
We prepare a file that provide the names of the SAC files together with the station names, the phase names, and the slowness vectors (sx,sy) describing how that part of the wavefield leaves the source region. The sx and sy values can be obtained using the statphase2slowvec program (https://github.com/stevenjgibbons/statphase2slowvec).
DPRK2_DPRK1_demo_list.txt is an example of such a file:
cc_trace_files/DPRK2_DPRK1_ABKAR_P_cc.sac ABKAR P -0.05770732 0.03931009
cc_trace_files/DPRK2_DPRK1_ASAR_P_cc.sac ASAR P 0.00499609 -0.05834497
cc_trace_files/DPRK2_DPRK1_BJT_Pn_cc.sac BJT Pn -0.12350800 -0.00679578
cc_trace_files/DPRK2_DPRK1_BVAR_P_cc.sac BVAR P -0.05910943 0.04524614
cc_trace_files/DPRK2_DPRK1_FINES_P_cc.sac FINES P -0.03314312 0.05195921
cc_trace_files/DPRK2_DPRK1_GERES_P_cc.sac GERES P -0.03279493 0.04146294
cc_trace_files/DPRK2_DPRK1_INCN_Pn_cc.sac INCN Pn -0.05676922 -0.10989843
cc_trace_files/DPRK2_DPRK1_INK_P_cc.sac INK P 0.02928058 0.05818984
cc_trace_files/DPRK2_DPRK1_JKA_Pn_cc.sac JKA Pn 0.11597879 0.04300383
cc_trace_files/DPRK2_DPRK1_MKAR_P_cc.sac MKAR P -0.07069660 0.03371665
cc_trace_files/DPRK2_DPRK1_NVAR_P_cc.sac NVAR P 0.03597500 0.03315638
cc_trace_files/DPRK2_DPRK1_PDAR_P_cc.sac PDAR P 0.03048417 0.03709658
cc_trace_files/DPRK2_DPRK1_TJN_Pn_cc.sac TJN Pn -0.03370203 -0.11901505
cc_trace_files/DPRK2_DPRK1_TXAR_P_cc.sac TXAR P 0.02867614 0.02966610
cc_trace_files/DPRK2_DPRK1_WRA_P_cc.sac WRA P 0.00600661 -0.06063249
cc_trace_files/DPRK2_DPRK1_YKA_P_cc.sac YKA P 0.02699689 0.05222468
An example run is given by the script run_demo_DPRK2_DPRK1_fk_loc.sh which sets up the name of the file and calls the python script fkrelloc.py.
On typing
sh run_demo_DPRK2_DPRK1_fk_loc.sh
you should obtain a text file providing an estimate of the location of event 1 relative to event 2:
cat plots/DPRK2_DPRK1_demo_fk_1.0_3.0.txt
plots/DPRK2_DPRK1_demo_fk_1.0_3.0 2.2400 -0.6000 105.0 2.3190
indicating that the location of event DPRK1 is estimated at 2.24 km to the East and 0.6 km to the South of event DPRK2.
It should also generate a png and pdf file of the overlaid cross-correlation traces (where the starting times are shifted relative to the start times of the waveform templates):
and of the f-k scan providing the relative location estimate:
If you publish using this code, I kindly ask you to cite the following paper:
Relative location of seismic events using broadband frequency-wavenumber analysis: Application to the North Korean Nuclear Test Site
Steven J. Gibbons, RAS Techniques and Instruments, rzag023, https://doi.org/10.1093/rasti/rzag023
