New Attenuation Relationship for Peak Ground and Pseudo-Spectral Acceleration of Normal-Faulting Earthquakes in Offshore Northeast Taiwan

Yu-Ju Wang ； Ya-Ting Lee ； Kuo-Fong Ma ； Yuan-Chieh Wu

《Terrestrial, Atmospheric and Oceanic Sciences》 27卷1期 (2016/02) Pp. 43-58

https://doi.org/10.3319/TAO.2015.08.17.01(T)

並列摘要

Ground motions from normal-faulting earthquakes are generally considered to be smaller than those of strike-slip and thrust events. On 11 April 2011 a crustal normal-faulting earthquake [the Fukushima earthquake (M_w 6.6)] occurred in Eastern Japan. The peak ground acceleration (PGA) observed was considerably higher than the predictions of several ground-motion prediction equations (GMPEs), which were derived mainly from thrust or strike-slip earthquakes. In northeast Taiwan, the tectonic structure of the Ryukyu Arc and the Okinawa Trough typically entail normal-faulting earthquakes. Because of the normal-faulting earthquakes relevance to ground motions and nuclear power plant sites in northeast Taiwan, we evaluated the impact of the ground motion of normal-faulting earthquakes in offshore northeast Taiwan using a newly constructed attenuation relationship for PGA and pseudo-spectral acceleration (Sa). We collected 832 records from 13 normal-faulting earthquakes with focal depths of less than 50 km. The moment magnitude (M_w) of the 13 events was between 4 - 6. The Sa and PGA of normal-faulting earthquakes offshore northeast Taiwan determined with the newly constructed attenuation relationship were higher and lower, respectively, than those obtained using attenuation equations commonly used in the Taiwan subduction zone.

並列關鍵字

GMPE ； Normal-faulting ； Attenuation ； PGA ； Sa ； Taiwan