Shear-wave splitting before and after the 1999 Xiuyan earthquake in Liaoning, China

• 来源期刊: 地震学报（英文版）
• 学科: 地球科学
• 年，卷（期）: 2008,（4）
• 页码范围: 344-357
• 页数: 14页
• 分类号: P315.3+1
• 语种: 英文

摘要

Using seismic waveform data recorded at station YK (Yingkou) of Liaoning Telemetry Digital Seismic Network, this paper studied the characteristics of shear-wave splitting before and after the Xiuyan Ms5.9 (M15.3) earthquake in November 29, 1999 with SAM method. The results show that the predominant polarizations of fast shear-waves at YK is in direction of ENE-WSW, consistent with the direction of regional principal compressive stress and also consistent with the direction of the regional tectonic stress field in North China; time-delays increasing before Xiuyan earthquake may shows accumulation of stress before earthquake. The predominant polarizations of fast shear-waves at YK are also related to the spatial distribution of small earthquakes and correlate with the fault strike. The histogram of monthly average polarizations of fast shear-waves shows that polarizations of fast shear-waves also seems to change from two months before the earthquake, but it still needs more data for verification.