A Generic Shear Wave Velocity Profiling Model for Use in Ground Motion Simulation

Yuxiang Tang,Jing Sun,Xinmei Xiang,Yongshan Zhang

doi:10.3390/geosciences10100408

Abstract

This study presents a generic model for constructing shear-wave velocity (VS) profiles for various conditions that can be used for modeling the upper-crustal modification effects in ground motion simulations for seismic hazard analysis. The piecewise P-wave velocity (VP) profiling model is adopted in the first place, and the VS profile model is obtained by combining the VP profiling model and VS/VP model. The used VS/VP model is constructed from various field measurements, experimental data, or CRUST1.0 data collected worldwide. By making the best use of the regionally/locally geological information, including the thickness of sedimentary and crystalline layers and reference VS values at specific depths, the VS profile can be constructed, and thus the amplification behavior of VS for a given earthquake scenario can be predicted. The generic model has been validated by four case studies of different target regions world around. The constructed profiles are found to be in fair agreement with field recordings. The frequency-dependent upper-crustal amplification factors are provided for use in stochastic ground motion simulations for each respective region. The proposed VS profiling model is proposed for region-specific use and can thus make the ground motion predictions to be partially non-ergodic.

Highlights

Seismic hazard analysis for the regions of low-to-moderate seismicity can be very challenging for the acute scarcity of strong-motion data in these regions, and such regions include southeasternAustralia (SEA) continent, eastern North America (ENA), and southeastern China (SEC)
The regional path factor can be identical within a tectonic region in ground motion modeling, and such path factor can be representative of the characteristics of ground motion attenuations within the whole region
The purpose of this study is to propose a more valid and comprehensive VS profiling model, which can be used to construct the region-specific VS profiles for various upper-crustal conditions and can be incorporated into stochastic simulations of ground motions as well as seismic hazard assessment procedures

Summary

Introduction

Seismic hazard analysis for the regions of low-to-moderate seismicity can be very challenging for the acute scarcity of strong-motion data in these regions, and such regions include southeasternAustralia (SEA) continent, eastern North America (ENA), and southeastern China (SEC). Seismic hazard analysis for the regions of low-to-moderate seismicity can be very challenging for the acute scarcity of strong-motion data in these regions, and such regions include southeastern. A realistic modeling approach for seismic hazard analysis purpose in stable continental regions (SCRs) and other intraplate regions (which are typically considered as low-to-moderate seismicity regions) can be achieved by combining the earthquake source effects, path effects, upper-crustal modification effects, and site conditions through stochastic simulations [1,2,3,4]. The sources factors and path factors are modeled to be site-specific in non-ergodic GMPEs [7])

Objectives

Discussion

Conclusion