← Back to Sessions

Multi-Scale Imaging of the Ridgecrest Area With Full-Wave Inversion of Regional and Dense Seismic Datasets

Description: 

There are several regional seismic velocity models for Southern California (e.g., CVMH, CVMS), but validation studies show that they all have poor resolution at the top 1-3 km of the crust, probably due to the lack of high-frequency input data. After the 2019 Ridgecrest mainshock, dense 2D and 1D nodes were deployed in the area with station spacings of ~5 km and ~100 m, respectively. Using data recorded by regional stations and those nodes, we aim to build a multi-scale velocity model via full-wave inversion of waveforms of numerous aftershocks and Green’s functions from ambient noise interferometry. The developed model will be self-consistent with detailed structures of rupture zones and the shallow crust embedded in the regional model. The regional model is inverted with a spatial grid of ~200 m from data recorded by regional stations and the 2D array. The rupture zone and shallow crust models are further refined by updating the regional model using local earthquake signals recorded by the dense 1D arrays and local grid size of 25 m. Waveforms from local events can be recorded with high SNR for frequencies of 10 Hz or more, capable of resolving small-scale features with size of ~50 m or less. The developed model can illuminate the multi-scale structure around fault zones and with depth, and it will allow deriving more accurate earthquake locations and source properties. The multi-scale model will also provide an improved framework for simulating dynamic earthquake ruptures and seismic motion.

Session: Multi-scale Models for Seismic Hazard Analysis

Type: Oral

Date: 4/20/2023

Presentation Time: 02:00 PM (local time)

Presenting Author: Guoliang Li

Student Presenter: No

Invited Presentation: 

Authors