2014年2月12日新疆于田地震强地面运动初步模拟及烈度预测

Preliminary simulation of strong ground motion for Yutian,Xinjiang earthquake of 12 February 2014,and hazard implication

2014年2月12日新疆自治区于田县发生了MS7.3级地震.在已知的三维介质模型、地形数据基础上,利用震源运动学初步反演模型(张勇等,2014),作者采用曲线坐标网格三维曲线有限差分方法模拟了于田地震波场传播过程,并计算了模拟区域地震烈度分布.结果表明:地震最大烈度为7度,距离震中最近的于田县城烈度约为5度,断层西北侧地面震动略强于断层东南侧.另外模拟结果还显示地震动在山脊处具有较大的幅度.该地震本身主要能量释放区域在中地壳,主要滑动未及地表,因此对地表造成的破坏有限,这与目前尚无人员伤亡报告的情况相符合.

A MS7.3 earthquake occurred at Yutian county,Xinjiang autonomous region,February 12,2014.With prepared data base including three-dimensional velocity model and topography data,as well as the preliminarily inverted kinematic source model（Zhang et al.2014）,we simulate the seismic wave propagation of Yutian earthquake with 3Dcurved grids finite-difference method,and calculate the distribution of seismic intensity for the modeling region.The simulation results reveal that the highest seismic intensity caused by this earthquakeis about 7degree.The intensity in the nearest down town of Yutian County is about 5degree.The ground motion at the northwestern side of the fault is slightly larger than that at the southeastern side.The simulation also suggests that ground motion has large amplitudes at the mountain peaks.Due to the fact that the main energy released area of this earthquake locates at the middle part of crust and the main rupture doesn′t reaches the Earth′s surface,the corresponding damages on ground surface is not severe,which coincides with the fact that there is no reported casualties up to present.