← Back to Sessions

Evaluation of Velocity Models of Sichuan-Yunnan Region on Strong Ground Motion Simulation

Description: 

The Sichuan-Yunnan region, located at the southeastern margin of the Tibetan Plateau, is characterized by complex geological structures and frequent seismic activity due to the collision between the Indian and Eurasian plates. Conducting physics-based quantitative simulations of strong ground motion can provide critical scientific support for earthquake disaster prevention and mitigation in this region. In recent years, researchers have developed several three-dimensional (3D) velocity structure models for the Sichuan-Yunnan region based on various datasets and methodologies. However, there remains a lack of systematic comparisons and evaluations of how different velocity models impact simulation results in strong ground motion modeling.

This study focuses on the September 5, 2022, Mw6.6 Luding earthquake as a case study. Using finite fault rupture processes derived from real data inversion and different velocity models, we conducted strong ground motion simulations. By comparing station-specific and spatially distributed PGV (peak ground velocity) and SA (spectral acceleration) values, we quantified the influence of different velocity models on simulation results. The findings aim to provide references for selecting velocity models in strong ground motion simulations for the region and offer insights into optimizing velocity models.

The tested velocity models include various regional and continental velocity models of China. Results indicate that in the high-shaking regions near the fault, source effects dominate, and the PGV distributions across models are largely consistent. Spatial distributions of the response spectrum reveal that shallow low-velocity structures and topographic effects significantly influence spectral characteristics. The average results from ensemble predictions using multiple velocity models align more closely with observed values, suggesting that combining multiple velocity models can enhance the accuracy of ground motion simulations in complex geological regions.

Session: Numerical Modeling in Seismology: Theory, Algorithms and Applications [Poster]

Type: Poster

Date: 4/17/2025

Presentation Time: 08:00 AM (local time)

Presenting Author: Tong

Student Presenter: Yes

Invited Presentation: 

Poster Number: 123

Authors