【摘要】 使用川滇地区三维走时表和三维速度模型,利用单纯形法对2011年3月10日云南盈江MS5.8地震进行了重新定位.震中位置为97.901°E,24.677°N;震源深度13.1km.使用双差定位方法对其余震序列进行了重定位.余震呈现明显的时空分布特征:余震主要分布在大盈江断裂的两侧及中段和北东段的转折处,余震带长度约12km;余震自西南沿大盈江断裂带北东段向北东方向移动,在大盈江断裂中段和北东段的交界处,余震逐渐向中段断裂移动;余震震源深度有向地表迁移的趋势,主震发生后10个小时内的余震最小深度接近2km,表明这次地震的破裂已接近地表.结合地震定位结果,作者认为这次地震震中位于盆地内部、深度浅、距县城近是导致本次地震破坏严重的主要原因.更多还原

【Abstract】 Based on the 3-D travel-time tables and 3-D velocity model of Sichuan--Yunnan region,we relocated the Yingjiang MS5.8 earthquake occurred in Yunnan Province on March 10,2011,by using the simplex algorithm.The relocated mainshock is 97.901°E,24.677°N,and the focal depth is 13.1 km.Aftershocks were relocated by applying the double-difference method.The aftershocks show obviously spatial and temporal variation,and mainly distribute along the two sides of Dayingjiang fault and near the junction of the middle and northeast section of Dayingjiang fault.The length of the aftershock zone is about 12 km.Aftershocks were moving from southwest to northeast along the northeast segment of Dayingjiang fault,while near the junction between the middle and northeast segment of Dayingjiang fault aftershocks were moving to the middle segment of Dayingjiang fault gradually.The focal depths of aftershocks tend to migrate to the surface.The minimum depth of aftershocks in the first 10 hours approached to 2 km,indicating that the rupture is close to the surface.Combined with the relocation result,we analyzed the factors causing damage to buildings.The main reasons for the destruction of buildings include that the epicenter is located in the basin,the focal depth is shallow,and the epicenter distance is short to Yingjiang city.更多还原