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使用横波分裂系统分析方法(SAM),对2014年5月30日盈江MS6.1地震震区内多个近场流动台站记录到的大量波形数据进行横波分裂研究.研究结果表明,盈江MS6.1地震序列的快S波偏振方向为近NS向,与区域主压应力方向一致.主震发生后,由于震源区应力状态的调整,卡场台(KAC)快S波偏振方向发生逆时针偏转,勐弄台(MNO)快S波偏振方向离散度减小,并且由于受到研究区内断裂的影响,MNO台偏振方向较KAC台偏振方向更加离散.KAC台和MNO台的慢S波时间延迟均表现出主震发生前短时间内突然减小,震后逐渐增大的变化特征,这意味着临震前震源区地壳应力的释放和震后地壳应力的增强,预示了后续余震的持续发生.地震序列时间延迟平均滑动曲线起伏振荡,表明了余震的发生伴随着震源区地壳应力的不断调整.
Using shear-wave Systematic Analysis (SAM), a large number of waveform data recorded by several near-field mobile stations in Yingjian MS6.1 earthquake area on May 30, 2014 were analyzed by shear-wave splitting. The results show that Yingjiang The fast S-wave polarization direction of MS6.1 earthquake sequence is near NS, which is consistent with the direction of principal compressive stress in the area. After the main shock occurred, due to the adjustment of the stress state in the focal zone, the fast S-wave polarization direction of KAC occurred Due to the influence of faults in MNO, the polarization direction of MNO is more discreet than that of KAC, and the slow S wave of KAC and MNO The time delay shows a sudden decrease in a short time before the main shock and a gradually increasing change after the earthquake, which means that the release of crustal stress and the increase of post-earthquake crustal stress in the pre-quake seismic source area indicate that the aftershock The occurrence of aftershocks was accompanied by the continuous adjustment of the crustal stress in the source area.