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
Since the late Cenozoic,the reactivated Tianshan orogenic belt has accommodated crustal shortening exceeding 200 km,primarily due to the far-field effects of the India-Eurasia plate collision.However,the details of th...Since the late Cenozoic,the reactivated Tianshan orogenic belt has accommodated crustal shortening exceeding 200 km,primarily due to the far-field effects of the India-Eurasia plate collision.However,the details of the strain partitioning in the Tianshan Mountain range remain elusive.We interpret a new compilation of GPS velocities covering the whole Tianshan range with a classic elastic block model.Compared to previous studies with a block modeling approach,the Tianshan orogenic belt is further subdivided into several blocks based on geological fault traces and a clustering analysis approach.In addition to obvious crustal shortening on the bounding thrust faults of the Tianshan,our inverted fault slip rates also reveal that faults within the Tianshan orogenic belt,such as the Nalati Fault and the southern margin of the Issyk-Kul Lake Fault,which plays a crucial role in accommodating the tectonic crustal shortening.In the 72°E-78°E region,the internal shortening rate within the mountain is approximately 5-7 mm/yr.Besides crustal shortening,strike-slip motion occurs on faults in the interior of the mountain range as well as in the foreland fold-and-thrust belts,especially in the southern margin of the Tianshan.These findings suggest that the crustal deformation in the Tianshan Mountain range is more complex than previously thought,and the oblique convergence between the Tarim Basin and the Tianshan probably results in both strike-slip and thrust motion.展开更多
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.
基金supported by Key R&D Program of Xinjiang Uygur Autonomous Region (2020B03006-2)National Key R&D Program of China (2022YFC3003703)+1 种基金Open Fund of Wuhan,Gravitation and Solid Earth Tides (WHYWZ202215)National Observation and Research Station and State Key Laboratory of Geodesy and Earth's Dynamics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences (SKLGED2023-2-5)。
文摘Since the late Cenozoic,the reactivated Tianshan orogenic belt has accommodated crustal shortening exceeding 200 km,primarily due to the far-field effects of the India-Eurasia plate collision.However,the details of the strain partitioning in the Tianshan Mountain range remain elusive.We interpret a new compilation of GPS velocities covering the whole Tianshan range with a classic elastic block model.Compared to previous studies with a block modeling approach,the Tianshan orogenic belt is further subdivided into several blocks based on geological fault traces and a clustering analysis approach.In addition to obvious crustal shortening on the bounding thrust faults of the Tianshan,our inverted fault slip rates also reveal that faults within the Tianshan orogenic belt,such as the Nalati Fault and the southern margin of the Issyk-Kul Lake Fault,which plays a crucial role in accommodating the tectonic crustal shortening.In the 72°E-78°E region,the internal shortening rate within the mountain is approximately 5-7 mm/yr.Besides crustal shortening,strike-slip motion occurs on faults in the interior of the mountain range as well as in the foreland fold-and-thrust belts,especially in the southern margin of the Tianshan.These findings suggest that the crustal deformation in the Tianshan Mountain range is more complex than previously thought,and the oblique convergence between the Tarim Basin and the Tianshan probably results in both strike-slip and thrust motion.