Multi-scale Analyses of Ridgecrest Earthquake Stress Drop
Description:
The Ridgecrest earthquake sequence was well recorded by the Ssouthern California earthquake Seismic Nnetwork (SCSN) and rapid response arrays. These dense observations provide an excellent opportunity to better understand the variabilities and uncertainties of earthquake source parameters. In this study, using the seismic network, we apply a stacking-based spectral analysis with depth-dependent attenuation corrections, and an empirical-Green’s-function (EGF) method in both frequency and time domain to the Ridgecrest earthquake sequence. We also apply the EGF method to a Distributed Acoustic Sensing (DAS) array with 1250 channels that recorded many aftershocks to measure the spectral ratio and relative source time function (RSTF). The 10-km long EW oriented DAS array is located to the Southwest of the Ridgecrest earthquake and recorded many aftershocks.
Systematic comparison of spectral ratio using from the seismic network shows overall consistency between different methods., Hhowever, we found that the time window and low-frequency bandwidth strongly influence the measured spectral ratio and corner frequencies. Events that show rupture complexity have larger discrepancy than simple events.
Comparison between DAS array and nearby seismic station SRT found good agreement in the shape of the spectral ratio. The RSTFs source time function resulted from complex spectral ratio shows good agreement., However, the time-domain deconvolution of DAS array data shows high degree of complexity, which is possibly from overfitting, and may need improvement. Our approach directly applies EGF analysis to the strain data recorded by DAS array without converting to velocity or acceleration. T, and the agreement from spectral analysis demonstrates the potential of directly using DAS for earthquake source parameter studies.
Session: Understanding the Variability in Earthquake Stress Drop Measurements
Type: Oral
Date: 4/20/2023
Presentation Time: 02:30 PM (local time)
Presenting Author: Xiaowei Chen
Student Presenter: No
Invited Presentation:
Authors
Xiaowei Chen Presenting Author Corresponding Author xiaowei.chen@tamu.edu Texas A&M University |
Jiuxun Yin yinjx@caltech.edu California Institute of Technology |
Colin Pennington pennington6@llnl.gov Lawrence Livermore National Laboratory |
Qimin Wu wu@lettisci.com Lettis Consultants International, Inc. |
Zhongwen Zhan zwzhan@gps.caltech.edu California Institute of Technology |
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Multi-scale Analyses of Ridgecrest Earthquake Stress Drop
Category
Understanding the Variability in Earthquake Stress Drop Measurements