Statistical Assessment for the Hazard of Large Aftershocks Post to the Chi-Chi Mainshock

集集主震後大餘震風險之統計評估

陳玉英(Yuh-Ing Chen) ； 黃啟軒(Chi-Shen Huang) ； 洪千惠(Chien-Hwei Hong)

《Terrestrial, Atmospheric and Oceanic Sciences》 15卷3期 (2004/09) Pp. 493-502

並列摘要

Real-time hazard assessment for large aftershocks from a major earthquake is usually needed for disaster relief and rescue efforts. In this paper, we employ the Reasenberg-Jones (RJ) model to describe the time-magnitude distribution of aftershocks after the Chi-Chi earthquake (M = 7.3, 1999/ 9/21). Both the maximum likelihood estimated RJ model and the Bayesian estimated RJ model are used to compute the probability of having at least one future M 5.0 aftershock. A probabilistic aftershock hazard map (PAHM) is also constructed for estimating the likely spatial distribution of M 5.0 aftershocks over the study region. This map gives then alarming for potential hazardous area of future M 5.0 aftershocks. Finally, we evaluate the association between the future M 5.0 aftershocks and the alarming obtained from the maximum likelihood estimated PAHM and Bayesian estimated PAHM, denoted by LPAHM and BPAHM, respectively. The results suggest that the LPAHM-based alarming is superior to the BPAHM-based one for locating future M 5.0 aftershocks after the Chi-Chi earthquake.

並列關鍵字

Aftershock hazard ； Bayesian estimate ； Conjugate prior distribution ； Maximum likelihood estimate