据地壳介质非均匀性判断郯庐断裂带鲁苏段未来大震位置

Location of Future Large Earthquakes in Jiangsu-Shandong Segment of the Tanlu Fault Zone from Crustal Media Inhomogeneity

从大尺度和小尺度两方面研究郯庐断裂带苏鲁段地壳介质非均匀性。使用地震波数据,研究了郯庐断裂带苏鲁段地壳速度结构的非均匀性,单位虚波Qmps的非均匀性,地壳介质泊松比的非均匀性,反映地壳介质小尺度非均匀性的分层κ值和y值。计算了1668年郯城81/2级地震震源区长度和沿断裂带的震源区边界,根据地震构造和地震活动性确定断裂的闭锁段,地震应力的积累单元和调整单元。对比1668年郯城81/2级地震的地壳介质状况,将各种非均匀性参数综合分析,结果表明,各种参数指向一致,未来大震的可能区域是33°—34.5°N,118°—118.8°E的北北东向区域,震级可达8级。

This paper studied the inhomogeneity of crustal medium in Jiangsu-Shandong segment of the Tanlu fault zone from large-and small-scale aspects.Using seismic data,the inhomogeneity of velocity structure,unit virtual wave,and Poisson ratio of crustal media were studied.The length of seismic source of the Tancheng M8.5 earthquake that occurred in 1668 was calculated,and the source region boundary along the Tanlu fault zone was determined.The locking section,accumulation unit,and adjustment unit of seismic stress were determined according to seismogenic tectonics and seismicity.Through analysis of the crustal media of the Tancheng M8.5 earthquake and various inhomogeneity parameters,we inferred that the possible region of future large earthquake is the NNE direction region with the range of 33°-34.5°N,118°-118.8°E,and the highest magnitude can reach M8.