Baseline correction for near-fault ground motion recordings of the 2008 Wenchuan Ms8.0 earthquake  

作　　者：Li Heng Wu Jianchao Yao Yunsheng Qin Xiaojun 

机构地区：[1]Key Laboratory of Earthquake Geodesy,Institute of Seismology,China Earthquake Administration,Wuhan 430071,China [2]Wuhan Institute of Earthquake Engineering,Wuhan 430071,China

出　　处：《Geodesy and Geodynamics》2012年第2期60-70,共11页大地测量与地球动力学（英文版）

基　　金：supported by the National Natural Science Foundation of China (41004020);the Director Foundation of Institute of Seismology,China Earthquake Administration (IS200926044)

摘　　要：In this study, both records of a digital accelerometer and a seismograph at a far-field station for the 2008 Ms8.0 Wenchuan earthquake were analyzed, and a pulsive noise model for acceleration record was found. By comparing with the result of a rotary-table tilt test, we concluded that the noises in the acceleration records were caused by ground tilt as a result of rotational ground motion. We analyzed the key noises that may cause baseline offset, and proposed a baseline-correction scheme for preserving the long-period ground motion in accordance with specific pulse positions. We then applied this correction method to some near-field strongmotion acceleration records. The result shows that this method can obtain near-field ground displacements, including permanent displacements, in agreement with GPS data, and that this method is more stable than other methods.In this study, both records of a digital accelerometer and a seismograph at a far-field station for the 2008 Ms8.0 Wenchuan earthquake were analyzed, and a pulsive noise model for acceleration record was found. By comparing with the result of a rotary-table tilt test, we concluded that the noises in the acceleration records were caused by ground tilt as a result of rotational ground motion. We analyzed the key noises that may cause baseline offset, and proposed a baseline-correction scheme for preserving the long-period ground motion in accordance with specific pulse positions. We then applied this correction method to some near-field strongmotion acceleration records. The result shows that this method can obtain near-field ground displacements, including permanent displacements, in agreement with GPS data, and that this method is more stable than other methods.

关 键 词：strong ground motion baseline correction permanent displacement rotational motion TILT 

分 类 号：P315.9[天文地球—地震学] TN305.7[天文地球—固体地球物理学]