Special Data Sets
Community Stress Drop Validation Study using the 2019 Ridgecrest Earthquake Sequence
Stress drop is a fundamental earthquake source parameter that in theory relates the average slip on a fault to rupture area, and in practice characterizes the high frequency seismic radiation. It is a key parameter in earthquake ground motion modeling, rupture simulation, and analysis of source physics. However, stress drops are notoriously variable and difficult to measure; estimates by different researchers, using different methods or datasets, yield highly inconsistent values which may mask physical trends. We propose a Community Stress Drop Validation Study using the 2019 Ridgecrest Earthquake Sequence to understand and resolve differences in stress drop measurement, in which many researchers from the community independently calculate and submit stress drop estimates using a consistent dataset of the 2019 Ridgecrest sequence of earthquakes. Rachel Abercrombie and Annemarie Baltay are leading the effort, which is now an official SCEC Technical Activity Group (TAG). support. This study is just starting up, and NOW is the perfect time to get involved. More information is available on the SCEC TAG website.
How to Participate Anyone is welcome and everyone is encouraged to join. You can download the data and perform analysis for stress drop. Corner frequency or other source parameters. You can become involved in the “meta-analysis”: comparing different results. You can just come to the workshop and see what’s going on! An upcoming SRL article will discuss the study in more detail. Sign up on the mailing listserv to stay aware of developments https://listserv.usgs.gov/mailman/listinfo/stressdrop-validation
Timeline: All events will be posted to the mailing list
- July 2021: Distribute a common dataset, accessible here (and announced to email list). We invite any and all interested to analyze the dataset for stress drop (or other relevant source parameters).
- August 2021: Details about uploading your initial results (corner frequency measurements, and other parameters and meta-data) for comparison and statistical analysis. Stay tuned to email list for details.
- November 2021: Initial (virtual) workshop to come together and discuss these results. Leading up to the workshop, we will ask participants to submit their analysis results and will begin some meta-analysis to compare them.
- December 2021: AGU session. Submit an abstract.
DatasetsPlease cite the References when using these datasets.
- Full Dataset: Dataset link. The .tar files starting on page 2 of the document have the links to the actual data and phase picks, grouped by magnitude. But please read through all of the other supporting documentation to understand the details of the assembled data, especially the Quick-reference guide example to help clarify things.
- Catalog of full data set, from relocations by Trugman (2020)
- Quick-reference guide with an example single earthquake.
- 1D velocity model specific to the source region that can be used for depth adjustments.
- Station Vs30 values and README
- For related information, see the Ridgecrest Special Data Sets webpage
- A Community Stress Drop Validation Study Using the 2019 Ridgecrest Earthquake Dataset. Baltay, A., Abercrombie, R. E., Taira, T. (2021), SSA Annual Meeting 2021.
- Trugman, D. T. (2020), Stress‐Drop and Source Scaling of the 2019 Ridgecrest, California, Earthquake Sequence. Bulletin of the Seismological Society of America 2020; 110 (4): 1859–1871. doi: 10.1785/0120200009
- Baltay, A. S., R. E. Abercrombie, T. Taira, A community stress drop validation study using the 2019 Ridgecrest Earthquake Sequence, Seismological Research Letters (in preparation)
- To cite any data from SCEDC see SCEDC Citation Policy