鄂尔多斯周缘地区中强震发生前地震矩加速释放时空特征

为研究鄂尔多斯周缘地区中强地震发生前地震矩加速释放时空特征,选取去丛集后的地震目录,基于地震矩释放程度m值,对1981年以来鄂尔多斯周缘地区10例MS≥5.5中强地震进行二维时空扫描,提取与地震矩加速释放特征相关的时空尺度作为矩释放程度时空扫描模型参数,以3个月为扫描步长,对震前12个月m值及累积Benioff应变释放进行拟合计算。结果显示,震前破裂成核点附近存在显著的AMR现象,7次震例存在累积Benioff应变加速释放特征,说明鄂尔多斯周缘地区MS≥5.5地震发生前AMR现象存在一定普遍性,应用矩加速时空扫描方法具有一定优势,但仍需结合其他方法进行综合分析。

Temporal and spatial characteristics of accelerating release of seismic moments before moderate earthquakes in the peripheral area of Ordos

To study the spatial and temporal characteristics of Accelerating Moment Release (AMR) before moderate earthquakes in the peripheral area of Ordos, 10 M_S ≥ 5.5 moderate earthquakes that occurred in the research area since 1981 were selected from an earthquake catalog after removing earthquake clusters and scanned in two dimensions based on the moment release m. The spatiotemporal scales related to accelerating release characteristics of seismic moments were extracted as the input parameters for the spatiotemporal scan model of moment release degree, and the m values and accumulated Benioff strain release 12 months before the earthquake were fitted using 3 months as the scan step. The results show that there is a significant AMR phenomenon near the nucleation point of the rupture before the earthquake, and there are accelerating release characteristics of the cumulative Benioff strain in 7 earthquakes, indicating that the AMR phenomenon is universal before moderate earthquakes with M_S ≥ 5.5 in the peripheral area of Ordos. The method has certain advantages, but it is still needed to combine with other methods for comprehensive analysis.