Benioff Strain Release Before Earthquakes in China: Accelerating or Not?
Benioff Strain Release Before Earthquakes in China: Accelerating or Not?
复制标题
DOI：
10.1007/s00024-006-0107-1
复制
发表时间：
2006-09
影响因子：
2
通讯作者：
Changsheng Jiang;Zhongliang Wu
中科院分区：
文献类型：
--
作者：
Changsheng Jiang;Zhongliang Wu
为了探讨强震和中强地震前被广泛讨论的加速矩释放现象的共性，我们系统地分析了1978年至2003年中国65次MS6.0以上地震前的贝尼奥夫应变释放。在这种方法中，选择一次强震或中等烈度地震作为“目标地震”，并在“目标地震”之前对地震活动进行回顾分析。分析中采用简单搜索区(以“目标地震”震中为中心的三个不同半径的圆形区域)和统一的时间范围(8年)。AMR是否存在，既要通过目测，也要通过幂函数曲线拟合来证明。研究发现，超过3/5的地震具有明显的震前AMR特征，1/3的地震似乎对搜索区敏感。AMR行为表现出明显的震源机制依赖性：在17个具有随搜索区域变化的稳定时刻释放特征的倾滑地震中，有15个表现出AMR行为，而在25个具有稳定时刻释放特征的走滑地震中，有16个表现出AMR行为。
We systematically analyzed the Benioff strain release before 65 earthquakes withMSover 6.0 in China from 1978 to 2003 to investigate the generality of the widely discussed accelerating moment release (AMR) phenomenon before strong and intermediate-strength earthquakes. In this approach, a strong or intermediate-strength earthquake is selected as a “target earthquake,” and retrospective analysis of seismic activity before the “target earthquake” is performed. Simple searching area (three circular areas with different radius centered at the epicenter of the “target earthquake”) and unified temporal range (8 years) are taken in the analysis. Justification of whether AMR exists is by both visual inspection and by power-law curve fitting. It is found that more than 3/5 of the earthquakes under consideration exhibit clear pre-shock AMR property, and 1/3 of the events seem to be sensitive to the searching area. AMR behavior shows apparent focal mechanism dependence: 15 out of 17 dip-slip earthquakes with stable moment release characteristics against the changing of searching areas exhibit AMR behavior, while 16 out of 25 strike-slip earthquakes with stable moment release characteristics exhibit AMR behavior.