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Comparisons between the 2016 USGS induced-seismicity hazard model and “Did You Feel It?” data

Isabel White, Taojun Liu, Nicolas Luco, & Abbie B. Liel

Published August 15, 2016, SCEC Contribution #6956, 2016 SCEC Annual Meeting Poster #247

The steep increase in seismicity rates in Oklahoma and southern Kansas led the U.S. Geological Survey (USGS) to develop a one-year induced seismicity probabilistic seismic hazard model for 2016 (Petersen et al., 2016). The increase has also led to a relatively large amount of ground motion and macroseismic intensity observations. In order to ground truth the model results, two databases were compared with the model: peak ground acceleration (PGA) values from instrumental data and intensity data from the “Did you feel it”? (DYFI?) system. As the 2016 hazard model was heavily weighted to the catalogs from 2014-2015, this study focuses on data from these years. The process involved converting hazard model results and any available ground motion data from PGA to Modified Mercalli Intensity (MMI) for comparison with the DYFI? data. A number of available conversions were tested; the one by Atkinson and Kaka (2007), which includes Central and Eastern U.S. data, proved to be best. The seismic data had to be declustered and the hazard model adjusted for site conditions to be more comparable. The annual exceedance rates were calculated with the DYFI? data for comparison to the model. The comparison was complicated by a number of issues related to the spatial and temporal completeness of the DYFI? data as described by Mak and Schorlemmer (2016). Furthermore, whereas the hazard model focuses on a higher range of ground motion, usually above about MMI IV or so, to date there are limited DYFI? data above IV from Oklahoma earthquakes. Most of the DYFI? responses are in the MMI II-IV range. Despite these limitations, comparisons at a number of key sites in the area show agreement in the annual rates of exceedance around MMI IV.

White, I., Liu, T., Luco, N., & Liel, A. B. (2016, 08). Comparisons between the 2016 USGS induced-seismicity hazard model and “Did You Feel It?” data. Poster Presentation at 2016 SCEC Annual Meeting.

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