In this paper,the shear wave splitting features of the Longtan reservoir area are studied by adopting the traditional cross-correlation coefficient method and polarization analysis,using the data recorded by the seism...In this paper,the shear wave splitting features of the Longtan reservoir area are studied by adopting the traditional cross-correlation coefficient method and polarization analysis,using the data recorded by the seismic network founded by a project under the National Science and Technology Pillar Program from April 2009 to April 2010.We found that most of polarization directions at seismic stations are consistent with the direction of the overall regional stress field,but local structures and faults may control or influence the fast shear-wave polarization direction.The time-delay normalized to source-station path is between 10 to 25ms/km,and among them,the time-delay is about 10ms/km at the LIL and XIL sites,which are farther away from the dam.The water depth is relatively shallow and seismic activity relatively weak after water storage,indicating the effect of reservoir water penetration,or loading,on the state of cracks in the reservoir area.We also found that the delay time changes consistently with the water level at stations DPD and GAL.It may be related to crack expansion and water penetration caused by the reservoir impoundment.展开更多
利用近7年的Gravity Recovery and Climate Experiment(GRACE)重力卫星资料,采用改进的滑动窗去相关滤波和扇形滤波技术计算了红水河上游区域的重力变化,结果显示红水河上游区域重力场有明显的上升趋势.利用Global Land Data Assimilati...利用近7年的Gravity Recovery and Climate Experiment(GRACE)重力卫星资料,采用改进的滑动窗去相关滤波和扇形滤波技术计算了红水河上游区域的重力变化,结果显示红水河上游区域重力场有明显的上升趋势.利用Global Land Data Assimilation Systems(GLDAS)土壤湿度模型计算了地表水对重力场的影响,结果表明土壤湿度变化对重力场的影响主要表现为季节变化特征,对该地区重力上升趋势的变化并没有明显的贡献.扣除土壤湿度影响之后的剩余重力变化曲线显示,在2006年9月前后该地区剩余重力有一约2.17μGal的重力抬升.报道资料和水库储水量模拟结果表明,这一重力抬升与我国在建第三大水电站——龙滩水电站水库蓄水有关.这一结果说明GRACE卫星不仅能够反映大尺度的季节变化信息,而且能够为监测大型水库水储量变化提供近实时的空间对地测量资料.展开更多
基金sponsored by the National Key Technology R&D Program(2008BAC38B02),China
文摘In this paper,the shear wave splitting features of the Longtan reservoir area are studied by adopting the traditional cross-correlation coefficient method and polarization analysis,using the data recorded by the seismic network founded by a project under the National Science and Technology Pillar Program from April 2009 to April 2010.We found that most of polarization directions at seismic stations are consistent with the direction of the overall regional stress field,but local structures and faults may control or influence the fast shear-wave polarization direction.The time-delay normalized to source-station path is between 10 to 25ms/km,and among them,the time-delay is about 10ms/km at the LIL and XIL sites,which are farther away from the dam.The water depth is relatively shallow and seismic activity relatively weak after water storage,indicating the effect of reservoir water penetration,or loading,on the state of cracks in the reservoir area.We also found that the delay time changes consistently with the water level at stations DPD and GAL.It may be related to crack expansion and water penetration caused by the reservoir impoundment.
文摘利用近7年的Gravity Recovery and Climate Experiment(GRACE)重力卫星资料,采用改进的滑动窗去相关滤波和扇形滤波技术计算了红水河上游区域的重力变化,结果显示红水河上游区域重力场有明显的上升趋势.利用Global Land Data Assimilation Systems(GLDAS)土壤湿度模型计算了地表水对重力场的影响,结果表明土壤湿度变化对重力场的影响主要表现为季节变化特征,对该地区重力上升趋势的变化并没有明显的贡献.扣除土壤湿度影响之后的剩余重力变化曲线显示,在2006年9月前后该地区剩余重力有一约2.17μGal的重力抬升.报道资料和水库储水量模拟结果表明,这一重力抬升与我国在建第三大水电站——龙滩水电站水库蓄水有关.这一结果说明GRACE卫星不仅能够反映大尺度的季节变化信息,而且能够为监测大型水库水储量变化提供近实时的空间对地测量资料.
