Earthquake Source Spectra Estimates Vary Widely for Two Ridgecrest, California, Aftershocks Because of Differences in Attenuation Corrections
Description:
Differences in stress-drop estimates among groups of scientists for the same earthquakes suggest disagreement in the shape of the source spectra that are used to measure corner frequency. A critical step in characterizing source spectra involves applying empirical corrections for site effects and the loss of high-frequency energy that occurs along the source-receiver path. As part of the Ridgecrest stress drop validation study, we compare path-corrected source spectra among different methods for two nearly co-located M3 earthquakes and investigate whether systematic differences in the applied path corrections are affecting corner-frequency estimates. We find substantial disagreements in the path corrections, which are well-approximated with a simple exponential function related to the strong ground motion parameter kappa. These kappa ;differences are strongly correlated with corner-frequency estimates for path-corrected spectra, suggesting they are a large source of systematic differences in corner frequency (and inferred stress drop) among the methods, reflecting varying tradeoffs between the source and path contributions to observed spectra. Because each method presumably fits the data it uses sufficiently well, these results indicate the limitations of existing purely empirical techniques to estimating path corrections and the need for new approaches.
Session: Advances in Reliable Earthquake Source Parameter Estimation [Poster]
Type: Poster
Date: 4/16/2025
Presentation Time: 08:00 AM (local time)
Presenting Author: Peter
Student Presenter: No
Invited Presentation:
Poster Number: 21
Authors
Peter Shearer Presenting Author Corresponding Author pshearer@ucsd.edu University of California, San Diego |
Ian Vandevert ivandevert@ucsd.edu University of California, San Diego |
Wenyuan Fan wenyuanfan@ucsd.edu University of California, San Diego |
Rachel Abercrombie rea@bu.edu Boston University |
Dino Bindi bindi@gfz-potsdam.de GFZ Potsdam |
Giovanna Calderoni giovanna.calderoni@ingv.it National Institute of Geophysics and Volcanology |
Xiaowei Chen xiaowei.chen@exchange.tamu.edu Texas A&M University |
William Ellsworth wellsworth@stanford.edu Stanford University |
Rebecca Harrington rebecca.harrington@ruhr-uni-bochum.de Ruhr University Bochum |
Yihe Huang yiheh@umich.edu University of Michigan, Ann Arbor, Michigan, United States |
Trey Knudson trey05@stanford.edu Stanford University, Palo Alto, California, United States |
Meggy Rossbach meggy.rossbach@ruhr-uni-bochum.de Ruhr University Bochum, Bochum, , Germany |
Claudio Satriano satriano@ipgp.fr Paris Cité University, Paris, , France |
Mariano Supino mariano.supino@ingv.it Paris Cité University, Paris, , France |
Daniel T Trugman dtrugman@unr.edu University of Nevada, Reno, Reno, Nevada, United States |
Hongfeng Yang hyang@cuhk.edu.hk Chinese University of Hong Kong, Hong Kong, , China |
Jiewen Zhang jwzhang@cuhk.edu.hk Chinese University of Hong Kong, Hong Kong, , China |
Earthquake Source Spectra Estimates Vary Widely for Two Ridgecrest, California, Aftershocks Because of Differences in Attenuation Corrections
Category
Advances in Reliable Earthquake Source Parameter Estimation