[关键词]
[摘要]
基于海南省地震台网2000 ~ 2013 年的区域地震波形数据,用剪切波分裂系统分析方法(SAM)获得了海南琼东北部地区“九五”数字台网中2个台站的剪切波分裂参数。结果表明,快剪切波偏振优势方向代表了原地最大主压应力方向。七星岭台NE方向的快剪切波偏振优势方向与区域水平主压应力场方向不一致,与NE走向的断裂一致,体现了局部构造和局部应力场的复杂性;青山岭NNE向的快剪切波偏振优势方向揭示了NNE走向断裂的构造意义。同时,本研究证实,位于活动断裂上或几条活动断裂交汇部位的台站的快剪切波偏振优势方向与对所选用的小地震起控制作用的活动断裂走向一致,而快剪切波偏振优势方向较为离散则反映了该区域复杂的断裂构造和应力分布特征。
[Key word]
[Abstract]
With SAM shear-wave splitting analysis,shear-wave splitting parameters of 2 stations at digital seismic stations are obtained in northeast of Hainan based on the data from 2000 to 2013 of Hainan Digital Seismic Network. The results show that the predominant polarization direction of fast share-wave indicates the direction of in-situ maximum principal compressive stress. The predominant polarizations of Qixingling seismic station are in NEE direction,which is different from the direction of principal compressive stress of Hainan area,but same with the strikes of faults in NE direction. It means that the local tectonic and stress field are complicated. The predominant polarizations of Qingshanling seismic station is in NNE-NS direction,which shows the significance of the strikes of the faults in NNE direction. At the same time,the study confirms that if the station is on active faults or at the junction of several active faults,the predominant polarization is parallel to the strikes of faults which control the earthquakes used in this analysis, and the predominant polarization is scattered which means that the background of faults and stress distribution are complicated.
[中图分类号]
[基金项目]
2013 年海南省地震局科研项目资助