Coda Derived Source Parameters

Description

This page collects consistent estimations of source parameters and source spectra for earthquakes recorded in different regions and ranging over a wide magnitude range. The consistency is due to the application of the same methodology, the coda calibration technique, developed by Mayeda et al. (2003) and recently implemented in a java-based code, the coda calibration tool (CCT, https://github.com/LLNL/coda-calibration-tool).
The main strength of the method is the use of narrowband coda waves measurements, which show low sensitivity to source and path heterogeneity. Additionally, we use independent ground-truth (GT) reference spectra for which apparent stresses are independently calculated through the coda spectral ratio (Mayeda et al., 2007), to break the path and site trade-off. The use of GT spectra eliminates the need to assume source scaling for the region, reducing the impact of a-priori model assumptions on the interpretation of scaling laws of source parameters and their variability.

Figure: A) Example source spectra summary page from CCT providing source parameter information such as seismic moment, Mw, total radiated energy and apparent stress. B) The corresponding interactive map showing the event and stations used. C) Example of coda envelopes for different stations at the frequency band 0.7-1 Hz for the considered event.

Acknowledgments

This study has been partially developed within the project Pianeta Dinamico Working Earth: geosciences and understanding of the Earth dynamics and natural hazards (CUP code D53J19000170001), funded by the Italian Ministry of University and Research (MIUR). Collaborators were supported as follows: D. Bindi was partially supported by the H2020 European project METIS (grant agreement 945121). K. Mayeda and J. Roman-Nieves were supported by the Air Force Technical Applications Center (AFTAC) at Patrick AFB, Satellite Beach, FL. Work by J. Barno and W.R.Walter was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

License

The provided seismic sources information are licensed under the terms of the "Creative Commons Attribution 4.0 International (CC BY 4.0)" License. This means that you are free to share (reproduce, distribute, communicate to the public, publicly display, perform and play this material in any medium and format) and adapt (remix and build upon the material for any purpose, even commercially). The licensor cannot revoke these freedoms as long as you follow the license terms. You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.

Disclaimer

This site provides access to the parametric tables containing source parameters and associated source spectra for different regions. Although all the parameters have been checked by analysts, no warranty, implicit or explicit is attached to the data. Every risk due to the improper use of data or the use of inaccurate information is assumed by the user.

References

• Mayeda K., Hofstetter A., O’Boyle J.L., Walter W.R. (2003) Stable and transportable regional magnitudes based on coda-derived moment rate spectra, Bull. seism. Soc. Am., 93, 224–239
• Mayeda K., Malagnini L., Walter W.R. (2007) A new spectral ratio method using narrow band coda envelopes: evidence for nonself- similarity in the Hector Mine sequence. Geophys. Res. Lett., 34. http://doi.org/10.1029/2007GL030041