Stochastic Finite-fault Ground Motion Simulation of the 2021 Mw5.9 Woods Point Earthquake: Facilitating Local Probabilistic Seismic Hazard Assessment
Description:
The 2021 MW5.9 Woods Point earthquake is the largest event in south-eastern Australia (SEA) recorded history since European settlement. To study its source and ground-motion characteristics and to extract information for local seismic hazard assessment, we employ a stochastic finite-fault simulation approach to simulate ground motions for this event based on the observations collected from 36 onshore stations. We determine the regional distance-dependent attenuation parameters using the horizontal Fourier acceleration amplitude spectrum (FAS) in the frequency range of 0.1-20 Hz. We parameterize the path parameters using different models to consider uncertainties and sensitivities. To investigate local site effects, we construct a local VS30-based site amplification model. Source parameters are then obtained by fitting the theoretical Brune’s ω2 model with a reference Fourier source spectrum at 1.0 km. The κ0 value of the reference rock site is estimated as 0.01 s, and the dynamic stress drop is found to be 41.0 MPa by minimizing the overall absolute residual of 5%-damped pseudo-spectral acceleration (PSA). We validate the simulations by comparing simulated and observed ground motions in terms of various intensity measurements; analyses of residuals show that the simulations are in good agreement with observations (average residual close to 0). To facilitate future probabilistic seismic hazard assessment (PSHA), six selected ground motion models (GMMs) are ranked using the deviance information criteria (DIC) based on an independent dataset of field observations and synthetic ground motions.
Session: High-frequency Ground Motion Measurements, Assessments and Predictions [Poster]
Type: Poster
Date: 4/18/2023
Presentation Time: 08:00 AM (local time)
Presenting Author: Yuxiang Tang
Student Presenter: No
Invited Presentation:
Authors
Yuxiang Tang Presenting Author Corresponding Author tangyuxiang56@gmail.com King Abdullah University of Science and Technology |
P. Martin Mai martin.mai@kaust.edu.sa King Abdullah University of Science and Technology |
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Stochastic Finite-fault Ground Motion Simulation of the 2021 Mw5.9 Woods Point Earthquake: Facilitating Local Probabilistic Seismic Hazard Assessment
Category
High-frequency Ground Motion Measurements, Assessments and Predictions