【摘要】 通过震源位置和速度结构联合反演方法,利用浙江和福建区域地震台网和珊溪水库台网给出的P波走时资料,得到了珊溪水库地区的三维速度结构,重新确定了珊溪水库地震的震源参数。结果表明:①震中总体呈现NW向分布,NW走向的双溪-焦溪垟断裂可能为珊溪水库地震序列的发震断层。②珊溪水库地震震源深度最大为9.5km,平均为5.4km,小于华南地震区10km的平均震源深度。③水库北、南两岸的地震较浅,震源深度均小于5km,水库淹没区地震较深。水库诱发地震之初的几年中震源深度有一个逐渐变大的过程,这可能是由于库水逐渐往深部下渗,从而进一步诱发了更深处的地震所致。④研究区存在一个低P波速度异常区,低速区位于水库淹没区内的多组断裂交汇部位,地震大多发生在低速异常区内。这可能与水库蓄水后库水下渗有关。更多还原

【Abstract】 Using the data of P wave travel time recorded at the Shanxi-reservoir seismological network and Zhejiang and Fujian provincial networks,we implemented a simultaneous inversion of earthquake relocation and velocity structure,got the new location of earthquake in the Shanxireservoir.The results show that:(1) The overall of epicenter to the distribution is to NW,the Shanxi-reservoir seismicity has a close relationship to the Shuangxi-Jiaoxiyang fault.(2) The focal depth of Shanxi-reservoir seismicity is 5.4km in an average,less than the average focal depth of earthquake zone in South China.(3) In the reservoir shore,the focal depth is shallower,and it is deeper in the reservoir inundation area.In the beginning of reservoir induced seismicity,focal depth increases gradually,and this may be due to the deep infiltration of water gradually induced a greater depth of the earthquake cause.(4) There is a low P wave velocity anomaly in the study area.Low-velocity zone in the reservoir inundation area is the intersection of multiple fracture sites.Shanxi-reservoir seismicity mostly occurred in the low-speed region.This may be related to water infiltration.更多还原