地震学报2011，Vol.33Issue(1)：1-14,14.DOI:10.3969/j.issn.0253-3782.2011.01.001
汶川地震前后地震波速比和视速度变化特征的研究
Temporal variation of vp/Vs vp and Vs before and after 2008 Wenchuan earthquake
摘要
Abstract
On May 12, 2008, a great earthquake of Ms8. 0 occurred on Longmenshan fault, Sichuan, China. With the stress change near-source region before and after the mainshock, would there have been corresponding physical property change of crust media? It became one of the hot questions in the research of Wenchuan earthquake. In this study we collected seismic phase data from January 1, 2001, to May 31, 2010, reported by Sichuan Digital Station Network of China Earthquake Administration (CEA), and the phase data from May 12 to September 30, 2008, reported by the Mobile Digital Seismic Network of Institute of Geophysics, CEA. We processed these data using the Wadati method. Based on the phase arrival times of selected direct wave Pg and Sg we paid special attention to the study of temporal variation of wave apparent velocity, and compared the velocity variation with the temporal variation of wave velocity ratio. To ensure the accuracy and stability of the calculated result, we carefully winnowed the data. Our research result shows that, in Longmenshan fault zone and its surrounding area, there was a 4 years' obvious decrease process of P- and S-wave apparent velocity before the Wenchuan earthquake,and at the time of half year before the earthquake an abrupt return appeared.Different from apparent velocity, the anomalous variation of wave velocity ratio showed a low amplitude decrease and lasted only for more than 2 years. But both wave velocity ratio and apparent velocity decrease returned fast at the time of half year before the mainshock.关键词
汶川地震/视速度/波速比Key words
Wenchuan earthquake/ apparent velocity/ wave velocity ratio分类
天文与地球科学引用本文复制引用
王林瑛,李艳娥,李芳,李广平,张天中,包淑娴,苏金蓉..汶川地震前后地震波速比和视速度变化特征的研究[J].地震学报,2011,33(1):1-14,14.基金项目
中国地震局地球物理研究所基本科研业务专项(DQJB08B17)和国家地震局监测预报司华北强震预报新技术专项(2012107)共同资助. 中国地震局地球物理研究所论著11AC1001. （DQJB08B17）
