The 90th Statistical Seismology seminar (online)

【Date & Time】
29 Aug, 2023 16:30-
Admission Free, No Booking Necessary
Meeting ID: 886 2106 7652
Passcode: 285994
Ming-Che Hsieh
Associate Research Fellow
Earthquake Disaster & Risk Evaluation and Management Center (E-DREaM), National Central University, Taiwan
Seismic Hazard Assessment for Metropolises and Sciences Parks in Taiwan: Analyzing Ground Motions Using Deterministic and Probabilistic Methods
Seismic hazard assessment (SHA) is essential for engineering constructions, hazard mitigation strategies, and earthquake-early warnings. The fundamental of SHA is based on analyzing empirical ground motion datasets and constructing ground motion models (GMMs) through parametrization and regression techniques. However, significant challenges arise due to the absence of (1) empirical ground motions from local large-magnitude earthquakes and (2) the incorporation of physical effects, such as source-rupture processes and complex wave propagation media, into a generalized functional form of GMM. To conquer these challenges in estimating ground motion, physics-based ground motion simulation is a powerful tool for deterministic seismic hazard assessment. In recent years, we have conducted ground motion simulations, taking great care to consider the characteristics of fault rupture, various scales of subsurface structures, basin geometry, high-resolution topographic relief, and more for earthquake scenarios in metropolitan areas and science parks in Taiwan. These results have been integrated into loss estimation and practical mitigation strategies. Furthermore, we have developed a short-term seismic intensity forecasting procedure for earthquake warnings based on the epidemic-type aftershock sequence (ETAS) and the ground motion model. Unlike traditional probabilistic seismic hazard analysis (PSHA), which provides the probability of ground motion exceeding certain levels over 30 or 50 years for engineering concerns, our forecasting model can deliver warning messages within a short period to facilitate timely decision-making. An example of the Taitung earthquake sequence in September 2022 demonstrates the good performance of forecasting seismic intensity.

Keywords: seismic hazard assessment, ground motion model, physics-based ground motion simulation, epidemic-type aftershock sequence