晋冀蒙交界区瑞利波速随时间变化特征

Temporal changes of Rayleigh wave velocity around Shanxi ProvinceHeibei Province-Inner Mongolia-Ji-Meng cross area

以冀晋蒙交界区为研究中心,利用2010年1月—2013年5月冀晋蒙交汇区部分数字地震观测台网资料,通过波形互相关,获取研究区内台站对之间瑞利波速度随时间的变化特征。结果表明,背景噪声互相关方法获取的相对地震波速度变化可用于监测地壳内部物性介质的变化,但在一定程度上受到季节变化影响。研究区瑞利波速度2011—2012年波动较大,可能是该时段环太平洋区强/大地震活动引起华北区应力场调整变化的反映,2013年后瑞利波速度变化基本在零值附近波动,表明研究区地下介质物性变化处于相对稳定阶段。

In this paper, we collect continue seismic wave data from broadband seismic stations de- ployed in the Shanxi Province-Heibei Province-Inner Mongolia cross area from January, 2010 to May, 2013. We use wave cross-correlation to measure the Rayleigh wave velocity changes between the station-pair. Our results show that this method can he used to monitor the medi- um changes of crustal. But it would be effect by the season variation. The Rayleigh wave ve- locity change presented large fluctuate during the year 2011 to 2012, which may relate to the strong earthquakes occurred around Pacific Rim during these time, and they in turn can cause the stress field adjustment in North China. After the year 2013, the curves of velocity fluctu- ation around zero may mean the study area underground medium property is in the stable stage, relatively.