Toward a Self-Consistent Mw Catalog for the Central Walker Lane Fault System
The Walker Lane Fault system is one of the most seismically active regions in the western U.S., and recently this region experienced several moderate earthquakes (M >= 5) including the 2020 M 6.5 Monte Cristo Range, 2020 M 5.2 Mono Lake, and the 2021 M 6.0 Antelope Valley sequences. A key to better understanding the tectonic stress is systematically evaluating the seismic moment and energy release of individual earthquakes. To develop a self-consistent moment magnitude (Mw) catalog for the Central Walker Lane seismicity, we used the coda magnitude method proposed developed by Mayeda & Walter (1996) and Mayeda et al., (2003) that provides a consistent measure of Mw over a broad range of event size using stable, coda-derived moment-rate source spectra. A total of 39 selected earthquakes (3.5 <= M <= 6.0) was used to calibrate station and path effects, coupled with independent ground-truth source spectra that were used to break the path and site effect trade-offs. We analyzed over 3000 envelope waveforms (11 narrow bands ranging between 0.05 and 10.0-Hz) collected at 19 broadband stations located in and around our target area. Our preliminary results find excellent agreement with waveform modeled moment tensors which will allow for stable estimates of Mw, well below what can be routinely and accurately waveform modeled. Furthermore, preliminary results suggest some of the Antelope Valley earthquakes are characterized by higher-stress drop than other western U.S. earthquakes. Additionally, events within the Sierra Nevada block also show higher stress, which is consistent with observed negative residuals of Mw-ML relative to other events in northern California.
Session: Earthquake Source Processes at Various Scales: Theory and Observations [Poster]
Type: Poster
Room: Evergreen Ballroom
Date: 4/21/2022
Presentation Time: 08:00 AM Pacific
Presenting Author: Taka'aki Taira
Student Presenter: No
Additional Authors
Taka'aki Taira Presenting Author Corresponding Author taira@berkeley.edu Berkeley Seismological Laboratory |
Kevin Mayeda kevin.mayeda@us.af.mil Air Force Technical Applications Center |
Jorge Roman-Nieves jorge.roman-nieves.1@us.af.mil Air Force Technical Applications Center |
Rengin Gok gok1@llnl.gov Lawrence Livermore National Laboratory |
William Walter walter5@llnl.gov Lawrence Livermore National Laboratory |
Douglas Dreger ddreger@berkeley.edu Berkeley Seismological Laboratory |
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Toward a Self-Consistent Mw Catalog for the Central Walker Lane Fault System
Category
Earthquake Source Processes at Various Scales: Theory and Observations
Description