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利用辽宁遥测数字地震台网营口台的地震波形资料,采用高原等剪切波分裂SAM分析方法,对1999年11月29日辽宁省岫岩MS5.9(ML5.3)地震前后的地震序列进行了剪切波分裂分析.通过对营口台的资料分析表明,快剪切波优势偏振方向为ENE--WSW向,与该地区主压应力方向一致,也与华北区域构造应力场方向一致;平均慢剪切波时间延迟在岫岩地震前显示增加,可能反映了震前的应力积累过程.营口台的快剪切波优势偏振方向还与小地震活动空间分布走向一致,与活动断层走向相关.快剪切波偏振的月平均变化直方图也显示,地震前两个月快剪切波偏振方向似乎也有变化,但这个现象还需要更多资料的证实.
Based on the seismic waveform data of Yingkou station of Liaoning Telemetry Digital Seismic Network, the seismic sequences before and after the Xiuyan MS5.9 (ML5.3) earthquake on November 29, 1999 in Liaoning Province were investigated by means of shear-wave split SAM analysis method such as plateau. The analysis of shear wave splitting data shows that the dominant polarization direction of fast shear - wave is ENE - WSW direction, which is consistent with the principal compressive stress direction in this area and also coincides with the tectonic stress field in North China. The average The time delay of slow shear wave shows an increase before Xiuyan earthquake, which may reflect the process of stress accumulation before the earthquake. The dominant polarization direction of fast shear wave in Yingkou station is also consistent with the spatial distribution of small seismic activity and is related to the strike of active fault. The histogram also shows that the polarization direction of the fast shear wave also appears to change in the first two months before the earthquake, but this phenomenon still needs more data to confirm.