Through numerical simulation for GPS data, aseismic negative dislocation model for crustal horizontal movement during 1999~2001 in the northeast margin of Qinghai-Xizang block is presented, combined with the spatial d...Through numerical simulation for GPS data, aseismic negative dislocation model for crustal horizontal movement during 1999~2001 in the northeast margin of Qinghai-Xizang block is presented, combined with the spatial distribution of apparent strain field in this area, the characteristics of motion and deformation of active blocks and their boundary faults, together with the place and intensity of strain accumulation are analyzed. It is shown that: a) 9 active blocks appeared totally clockwise motion from eastward by north to eastward by south. Obvious sinistral strike-slip and NE-NEE relative compressive motion between the blocks separated by Qilianshan-Haiyuan fault zone was discovered; b) 20 fault segments (most of them showed compression) locked the relative motion between blocks to varying degrees, among the total, the mid-east segment of Qilianshan fault (containing the place where it meets Riyueshan-Lajishan fault) and the place where it meets Haiyuan fault and Zhuanglanghe fault, more favored accumulation of strain. Moreover, the region where Riyueshan-Lajishan fault meets north boundary of Qaidam block may have strain accumulation to some degree. c) Obtained magnitude of block velocities and locking of their boundaries were less than relevant results for observation in the period of 1993~1999.展开更多
On the basis of the velocity field results of horizontal crustal movement obtained from GPS measurements during the periods of 1993-1999, 1999-2001 and 2001-2003 in the northeastern margin of Qinghai-Xizang block, and...On the basis of the velocity field results of horizontal crustal movement obtained from GPS measurements during the periods of 1993-1999, 1999-2001 and 2001-2003 in the northeastern margin of Qinghai-Xizang block, and by the inversion of negative dislocation model for the elastic block boundaries, we provide in this paper a qualitative analysis and quantitative description for the difference of motion and deformation between the tectonic blocks and their boundary faults, time-space distribution of tectonic strain field, and locations with highly accumulated strain energy and correlative intensity. Furthermore, taking the regional tectonics and block strain into full consideration, we investigate the common features of background precursors relating to location prediction for M greater than or equal 6 earthquakes.展开更多
基金State Key Basic Development and Programming Project Mechanism and Prediction of Continental Strong Earthquakes (G1998040703) Joint Seismological Science Foundation of China (603001).
文摘Through numerical simulation for GPS data, aseismic negative dislocation model for crustal horizontal movement during 1999~2001 in the northeast margin of Qinghai-Xizang block is presented, combined with the spatial distribution of apparent strain field in this area, the characteristics of motion and deformation of active blocks and their boundary faults, together with the place and intensity of strain accumulation are analyzed. It is shown that: a) 9 active blocks appeared totally clockwise motion from eastward by north to eastward by south. Obvious sinistral strike-slip and NE-NEE relative compressive motion between the blocks separated by Qilianshan-Haiyuan fault zone was discovered; b) 20 fault segments (most of them showed compression) locked the relative motion between blocks to varying degrees, among the total, the mid-east segment of Qilianshan fault (containing the place where it meets Riyueshan-Lajishan fault) and the place where it meets Haiyuan fault and Zhuanglanghe fault, more favored accumulation of strain. Moreover, the region where Riyueshan-Lajishan fault meets north boundary of Qaidam block may have strain accumulation to some degree. c) Obtained magnitude of block velocities and locking of their boundaries were less than relevant results for observation in the period of 1993~1999.
基金Joint Seismological Science Foundation (603001)Project of China Earthquake Administration during the tenth five-year (100501-04).
文摘On the basis of the velocity field results of horizontal crustal movement obtained from GPS measurements during the periods of 1993-1999, 1999-2001 and 2001-2003 in the northeastern margin of Qinghai-Xizang block, and by the inversion of negative dislocation model for the elastic block boundaries, we provide in this paper a qualitative analysis and quantitative description for the difference of motion and deformation between the tectonic blocks and their boundary faults, time-space distribution of tectonic strain field, and locations with highly accumulated strain energy and correlative intensity. Furthermore, taking the regional tectonics and block strain into full consideration, we investigate the common features of background precursors relating to location prediction for M greater than or equal 6 earthquakes.
