第99回統計地震学セミナー / The 99th Statistical Seismology Seminar

【Date＆Time】
31 October 2024　13:30-15:30
Admission Free, No Booking Necessary
【Place】
online (with zoom) and 4F Lounge (ISM)
Zoom meeting:
https://us06web.zoom.us/j/82162720531?pwd=WsIjbaJpkhaYkJMEB4eRocIQbqeADN.1
Meeting ID: 821 6272 0531
Passcode: 551420
Location: 4F Lounge
【Speaker1】
Ming-Che Hsieh
(Earthquake Disaster & Risk Evaluation and Management Center (E-DREaM), National Central University, Taoyuan, Taiwan)
【Title】
Toward Real-Time Ground-Shaking-Intensity Forecasting Using ETAS and GMM: Insights from the Analysis of Recent Large Earthquake Sequences in Taiwan, and Its Potential Applications
【Abstract】
Earthquake forecasting, combined with precise ground-shaking estimations, plays a pivotal role in safeguarding public safety, fortifying infrastructure, and bolstering the preparedness of emergency services. This study introduces a comprehensive workflow that integrates the epidemic-type aftershock sequence (ETAS) model with a pre-selected ground-motion model (GMM), facilitating accurate short-term forecasting of ground-shaking intensity, which is crucial for effective earthquake warning. At first, an analysis was conducted on an earthquake catalog spanning from 1994 to 2022 to optimize the ETAS parameters. The dataset used in this analysis allowed for the further calculation of total, background, and clustering seismicity rates, which are crucial for understanding spatiotemporal earthquake occurrence. Subsequently, short-term earthquake activity simulations were performed using these update-to-date seismicity rates to generate synthetic catalogs. The ground-shaking impact on the target sites from each synthetic catalog was assessed by determining the maximum intensity using a selected GMM. This simulation process was repeated to enhance the reliability of the forecasts. Through this process, a probability distribution was created, serving as a robust forecasting for ground-shaking intensity at sites. The performance of the forecasting model was validated through two examples of the Taitung earthquake sequence in September 2022, and the Hualien earthquake sequence in April 2024, showing the workflow’s effectiveness in forecasting earthquake occurrences and site-specific ground-shaking probability estimations. The proposed forecasting model can quickly deliver short-term seismic hazard curves and warning messages, facilitating timely decision-making. The possible applications of the workflow will also be presented.
【Reference】
Ming‐Che Hsieh, Chung‐Han Chan, Kuo‐Fong Ma, Yin‐Tung Yen, Chun‐Te Chen, Da‐Yi Chen, Yi‐Wun Mika Liao; Toward Real‐Time Ground‐Shaking‐Intensity Forecasting Using ETAS and GMM: Insights from the Analysis of the 2022 Taitung Earthquake Sequence. Seismological Research Letters 2024; doi: https://doi.org/10.1785/0220240180
【Speaker2】
Giuseppe Petrillo
(Earth Observatory of Singapore,Nanyang Technological University (NTU), Singapore Scuola Superiore Meridionale, Naples, Italy)
【Title】
The Impact of Stress Redistribution on the Spatial and Magnitude Patterns of Future Earthquakes
【Abstract】
Predicting the location and timing of the next major earthquake remains a critical challenge in seismic forecasting. While it seems logical that future earthquakes will occur in regions where stress has accumulated from previous events, most forecasting models do not consider the relationship between stress distribution and earthquake occurrence. In this study, we utilize a physical earthquake simulator to investigate how stress redistribution influences the likelihood of large earthquakes and aftershocks. Our results show that major earthquakes are more likely to initiate near the edges of previous ruptures, where stress has not yet been fully released. Additionally, we explore how this redistribution of stress affects the magnitude distribution of subsequent aftershocks. These findings provide valuable insights for improving earthquake forecasting models by incorporating stress evolution, potentially enhancing their predictive accuracy.