亚洲地区Benioff应变释放和强震活动的周期性特征研究

为研究亚洲地区强震Benioff应变释放和周期性活动特征, 本研究采用了1900—1999年的IASPEI百年目录和2000—2008年的全球CMT目录组成的混合目录, 分别考察了亚洲地区1900—2008年M_W6.9以上强震的Benioff应变释放时间演化、 深浅源地震的累积Benioff应变线性偏离和M_W8.0以上强震周期性活动的Rydelek-Sacks检验三方面内容。结果表明, Benioff应变释放整体上大致存在30年左右的强弱起伏; 深、 浅源地震的累积Benioff应变线性偏离具有不同的周期性活动, 其中深源地震约为40年左右, 浅源地震具有更长的活动周期; M_W8.0以上强震的发生存在33±2年的周期性活动。作为结果的外推, 亚洲地区未来10年的强震活动正处于以1990—2020年为活动周期的后三分之一阶段, 应变释放水平相对2000—2010年较低, 可能与1990—2000年的水平相当。

Benioff Strain Release and Periodic Characteristics of Strong Earthquake Activities in Asia

In this study, Benioff strain release and the cyclical characteristics of strong earthquake(M_W>8.0) activities since 1900 in the Asian region are investigated based on the mixed catalogue of the Centennial Catalogue edited by Engdahl and Villasenor and the global CMT catalogue. Temporal Benioff strain release using earthquake with M_W≥6.9, cumulative Benioff strain linear deviation using different source depths of earthquakes and periodic Rydelek-Sacks test for M_W>8.0 earthquake activity are analyzed, respectively. The results show that there is an aproximate 30 years or less fluctuation of strength in the Benioff strain release; cumulative Benioff strain linear deviation has different cyclical activities, 40 years for deep earthquakes and longer active for shallow earthquakes; and there is a 33±2 years of cyclical activity of M_W>8.0 strong earthquakes. As a result of extrapolation, Asian region might be in a strong earthquake activity in the next 10 years, occurring in the third stage of the 1990 to 2020 cycle. The level of strain release will be lower than that from 2000 to 2010, and aproximately the same level with the period from 1990 to 2000.