2012年4月11日苏门答腊北部附近海域发生MW=8.6地震,国际上采用不同数据获得了该地震的断层滑动模型,但断层走滑性质存在较大差异.卫星重力GRACE(Gravity Recovery and Climate Experiment)观测覆盖震中区域,可以提供很好的断层参数估...2012年4月11日苏门答腊北部附近海域发生MW=8.6地震,国际上采用不同数据获得了该地震的断层滑动模型,但断层走滑性质存在较大差异.卫星重力GRACE(Gravity Recovery and Climate Experiment)观测覆盖震中区域,可以提供很好的断层参数估计约束.本文采用GRACE月重力场模型数据提取了此次地震同震重力和重力梯度变化,表明了北向分量的优越性.并与断层模型理论计算结果进行了比较,分析了Txx(北-北向重力梯度)分量对断层参数的敏感性,以及基于粒子群算法以及Okubo位错模型反演了该地震断层参数.结果表明GRACE观测到的同震重力梯度变化在空间形态分布上与断层模型模拟结果符合较好,但振幅差异较大.重力和重力梯度的北向分量可以很好地压制条带误差,其中gN(北向重力变化)和Txx的误差最小,其次是Txz(北-上向重力梯度),误差最大和对条带误差抑制效果最差的是Txy(北-东向重力梯度).Txx对断层的深度不敏感,对其余断层参数较敏感.基于GRACE反演得到的断层的走向角为113.63°,倾角为89.99°,滑移角为175.26°,平均滑移量为28.18m,相应的矩震为8.71级,且此次地震的走滑性质为右旋走滑.展开更多
In this article, the energy balance method is used to retrieve thermospheric mass density from CHAMP satellite precise orbit determination(POD) data during 2007–2009. The retrieved thermospheric mass densities are co...In this article, the energy balance method is used to retrieve thermospheric mass density from CHAMP satellite precise orbit determination(POD) data during 2007–2009. The retrieved thermospheric mass densities are compared with those from accelerometer data and an empirical model. The main conclusions are as follows:(1) Thermospheric mass density can be retrieved from POD data by the energy balance and semi-major axis decay methods, whose results are consistent.(2) The accuracy of the retrieved densities depends on the integration time period, and the optimal period for CHAMP density retrieval from POD data is about 20 minutes.(3) The energy balance method can be used to calibrate accelerometer data.(4) The accuracy of retrieving thermospheric density from POD data varies with satellite altitude and local time.展开更多
文摘2012年4月11日苏门答腊北部附近海域发生MW=8.6地震,国际上采用不同数据获得了该地震的断层滑动模型,但断层走滑性质存在较大差异.卫星重力GRACE(Gravity Recovery and Climate Experiment)观测覆盖震中区域,可以提供很好的断层参数估计约束.本文采用GRACE月重力场模型数据提取了此次地震同震重力和重力梯度变化,表明了北向分量的优越性.并与断层模型理论计算结果进行了比较,分析了Txx(北-北向重力梯度)分量对断层参数的敏感性,以及基于粒子群算法以及Okubo位错模型反演了该地震断层参数.结果表明GRACE观测到的同震重力梯度变化在空间形态分布上与断层模型模拟结果符合较好,但振幅差异较大.重力和重力梯度的北向分量可以很好地压制条带误差,其中gN(北向重力变化)和Txx的误差最小,其次是Txz(北-上向重力梯度),误差最大和对条带误差抑制效果最差的是Txy(北-东向重力梯度).Txx对断层的深度不敏感,对其余断层参数较敏感.基于GRACE反演得到的断层的走向角为113.63°,倾角为89.99°,滑移角为175.26°,平均滑移量为28.18m,相应的矩震为8.71级,且此次地震的走滑性质为右旋走滑.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41325017 & 41274158)
文摘In this article, the energy balance method is used to retrieve thermospheric mass density from CHAMP satellite precise orbit determination(POD) data during 2007–2009. The retrieved thermospheric mass densities are compared with those from accelerometer data and an empirical model. The main conclusions are as follows:(1) Thermospheric mass density can be retrieved from POD data by the energy balance and semi-major axis decay methods, whose results are consistent.(2) The accuracy of the retrieved densities depends on the integration time period, and the optimal period for CHAMP density retrieval from POD data is about 20 minutes.(3) The energy balance method can be used to calibrate accelerometer data.(4) The accuracy of retrieving thermospheric density from POD data varies with satellite altitude and local time.
