Rotational Motions Recorded at Hualien During the 2012 Wutai, Taiwan Earthquake

Abstract

It is widely accepted that the effects of rotational motions on seismic waves can be neglected when ground motion is small and might be underestimated in near-fault and/or with extremely large ground motions. However, quantitative validation of these assumptions is still needed. During the 2012 Wutai earthquake in Taiwan (6.4 ML), a set of small rotation rate-strong motion velocity data was recorded at the HWLB (Hualien) seismographic station. This station is 161 km away from the epicenter and the recorded peak ground acceleration and rotation rate are about 7 cm s-1 s-1 and 0.1 mrad s-1, respectively. This data set is useful for evaluating the lower bound of ground motion that can be neglected regarding the effects of rotational motions.

Keywords

• Wutai earthquake
• Rotational motions
• Strong motion
• Centrifugal acceleration