据新疆地震台网测定,2019年10月27日13时29分,新疆阿克苏地区乌什县发生MS5.0地震(以下简称乌什MS5.0地震),震中为41.21°N,78.82°E,震源深度11 km,当天18时52分再次发生MS4.5地震,地震类型为多震型。地震震源机制的确定,对于...据新疆地震台网测定,2019年10月27日13时29分,新疆阿克苏地区乌什县发生MS5.0地震(以下简称乌什MS5.0地震),震中为41.21°N,78.82°E,震源深度11 km,当天18时52分再次发生MS4.5地震,地震类型为多震型。地震震源机制的确定,对于研究地震的发震机制,孕震机理以及震后应力的分布,具有非常重要的意义[1-5]。早期的地震矩张量大都是由P波初动符号确定,如高国英等(1998)采用P波初动的方法计算1997年伽师强震群6级以上地震的震源机制解,确定了伽师震群的破裂面[6]。利用宽频带地震波形记录来反演地震矩张量可以避开P波初动求解震源机制的苛刻条件,可以得到整个地震破裂过程的信息。本文中利用目前较流行的CAP(Cut and Paste)方法快速计算了乌什MS5.0和MS4.5地震震源机制解,对于判定未来地震活动趋势具有重要意义,为震源区及其邻区的构造应力场积累了基础资料。展开更多
Based on the seismic data recorded by the China Earthquake Networks Center(CENC) in the Luxian area from January 2009 to October 2021,the 3D V_P,V_S, V_P/V_S structures and seismic locations of the area are obtained b...Based on the seismic data recorded by the China Earthquake Networks Center(CENC) in the Luxian area from January 2009 to October 2021,the 3D V_P,V_S, V_P/V_S structures and seismic locations of the area are obtained by joint inversion using the V_P/V_S model consistency-constrained double-difference tomography method(tomoDDMC).The earthquakes in the study area are mainly concentrated at a depth of 2-6 km,and the focal depth is generally shallow.The Ms 6.0 Luxian earthquake occurred at the transition zone of high-and low-velocity anomalies and the aftershock sequence was distributed along the edge of the low-V_P zone.A small number of foreshocks occurred on the west side of the M_S 6.0 Luxian earthquake,while most of the aftershocks were distributed on the east side of the M_S 6.0 Luxian earthquake.The aftershock sequence consisted of three seismic bands with different trends,and the overall distribution was in a NWW direction,which was inconsistent with the spatial distribution of the main active faults nearby.In addition,the spatiotemporal distribution of earthquakes and the variation of b-values are closely related to the industrial water injection activities in the study area,reflecting the activation of pre-existing hidden faults under certain tectonic and stress environments leading to seismic activities in the area.展开更多
文摘据新疆地震台网测定,2019年10月27日13时29分,新疆阿克苏地区乌什县发生MS5.0地震(以下简称乌什MS5.0地震),震中为41.21°N,78.82°E,震源深度11 km,当天18时52分再次发生MS4.5地震,地震类型为多震型。地震震源机制的确定,对于研究地震的发震机制,孕震机理以及震后应力的分布,具有非常重要的意义[1-5]。早期的地震矩张量大都是由P波初动符号确定,如高国英等(1998)采用P波初动的方法计算1997年伽师强震群6级以上地震的震源机制解,确定了伽师震群的破裂面[6]。利用宽频带地震波形记录来反演地震矩张量可以避开P波初动求解震源机制的苛刻条件,可以得到整个地震破裂过程的信息。本文中利用目前较流行的CAP(Cut and Paste)方法快速计算了乌什MS5.0和MS4.5地震震源机制解,对于判定未来地震活动趋势具有重要意义,为震源区及其邻区的构造应力场积累了基础资料。
基金supported by the Fundamental Research Funds for the Institute of Earthquake Forecasting, China Earthquake Administration(CEAIEF20220211 and CEAIEF20220401)。
文摘Based on the seismic data recorded by the China Earthquake Networks Center(CENC) in the Luxian area from January 2009 to October 2021,the 3D V_P,V_S, V_P/V_S structures and seismic locations of the area are obtained by joint inversion using the V_P/V_S model consistency-constrained double-difference tomography method(tomoDDMC).The earthquakes in the study area are mainly concentrated at a depth of 2-6 km,and the focal depth is generally shallow.The Ms 6.0 Luxian earthquake occurred at the transition zone of high-and low-velocity anomalies and the aftershock sequence was distributed along the edge of the low-V_P zone.A small number of foreshocks occurred on the west side of the M_S 6.0 Luxian earthquake,while most of the aftershocks were distributed on the east side of the M_S 6.0 Luxian earthquake.The aftershock sequence consisted of three seismic bands with different trends,and the overall distribution was in a NWW direction,which was inconsistent with the spatial distribution of the main active faults nearby.In addition,the spatiotemporal distribution of earthquakes and the variation of b-values are closely related to the industrial water injection activities in the study area,reflecting the activation of pre-existing hidden faults under certain tectonic and stress environments leading to seismic activities in the area.
