We obtain a unified horizontal velocity field of continental China and vicinity through measurements at 81 GPS stations provided by the National Key Infrastructure Project, Crustal Movement Observation Network of Chin...We obtain a unified horizontal velocity field of continental China and vicinity through measurements at 81 GPS stations provided by the National Key Infrastructure Project, Crustal Movement Observation Network of China. The velocity field delineates patterns of movements and deformation of active crustal blocks in continental China under the Eurasia-fixed reference frame. The space-based geodesy also clearly shows for the first time the horizontal movementand deformation of continental China induced by indentation of the Indian plate. The data provide kinematic constraints for simulating dynamic process of continental litho-spheric deformation.展开更多
Based on the precise reieveling data of more than 260,000 km carried out from 1950 to 1991 in the Chinese mainland,recent crustal vertical movement is studied.By means of some quantitative indices,such as the pattern ...Based on the precise reieveling data of more than 260,000 km carried out from 1950 to 1991 in the Chinese mainland,recent crustal vertical movement is studied.By means of some quantitative indices,such as the pattern of crustal vertical movement,the intensity of differential movement,the maximum gradient and its distribution,etc.,the properties of movements are analyzed on a large scale.The results suggest that all the properties have a profound tectonic background of their own and are closely related to the zoning and seismic activity of active subplates.The driving force for the movement comes mainly from the northward push of the India plate acting on the Eurasia plate.The effects of motions of the Pacific and Philippine Sea plates in the east are much less significant.展开更多
Based on the data from repeated precise leveling and across-fault deformation measurements carried out in recent 30 years and the analyzed results from GPS observations made in recent years along the northeastern marg...Based on the data from repeated precise leveling and across-fault deformation measurements carried out in recent 30 years and the analyzed results from GPS observations made in recent years along the northeastern margin of Qinghai-Xizang block, and combined with the geological structures and seismic activities, some characteristics in regional tectonic deformation and strong earthquake development are studied and approached preliminarily. The results show that: a) The space-time distribution of current tectonic deformation in this area is inhomogeneous with relatively intensive tectonic deformation in the vicinity of main boundary faults and weak deformation in the farther areas. The intensity of vertical differential movement and the deformation status vary with time, and the horizontal movement and deformation are characterized by apparent compression and strike-slip. b) The tectonic stress field generated by the NE-trending continuous compressive movement of Qinghai-Xizang block due to the northward press and collision of India plate is the principal stress for the tectonic deformation and earthquake development in this area. The evolution of space-time distribution of tectonic deformation and seismicity is closely related to the block activity and dynamic evolution of regional tectonic stress field. c) The vertical deformation uplift and high-gradient deformation zones and the obvious fault deformation anomaly appeared along the boundaries of tectonic blocks can be considered as the indicators of hindered block motion and intensified tectonic stress field for strong earthquake development. Usually, the above-mentioned phenomena would be followed by the seismicity of M6.0, but the earthquake might not occur in the place with the maximum movement. The zones with the fault deformation anomaly characterized by tendencious accumulation acceleration turning and the surrounding areas might be the positions for accumulation of strain energy and development and occurrence of strong earthquakes.展开更多
基金This work was jointly supported by the Project of Crustal Movement Observation Network of China and the National Natural Science Foundation of China (Grant No. 49834002).
文摘We obtain a unified horizontal velocity field of continental China and vicinity through measurements at 81 GPS stations provided by the National Key Infrastructure Project, Crustal Movement Observation Network of China. The velocity field delineates patterns of movements and deformation of active crustal blocks in continental China under the Eurasia-fixed reference frame. The space-based geodesy also clearly shows for the first time the horizontal movementand deformation of continental China induced by indentation of the Indian plate. The data provide kinematic constraints for simulating dynamic process of continental litho-spheric deformation.
文摘Based on the precise reieveling data of more than 260,000 km carried out from 1950 to 1991 in the Chinese mainland,recent crustal vertical movement is studied.By means of some quantitative indices,such as the pattern of crustal vertical movement,the intensity of differential movement,the maximum gradient and its distribution,etc.,the properties of movements are analyzed on a large scale.The results suggest that all the properties have a profound tectonic background of their own and are closely related to the zoning and seismic activity of active subplates.The driving force for the movement comes mainly from the northward push of the India plate acting on the Eurasia plate.The effects of motions of the Pacific and Philippine Sea plates in the east are much less significant.
基金Foundation item: The Development Program on National Key Basic Researches under the Project Mechanism and Prediction of Continental strong Earthquakes (G1998040703)
文摘Based on the data from repeated precise leveling and across-fault deformation measurements carried out in recent 30 years and the analyzed results from GPS observations made in recent years along the northeastern margin of Qinghai-Xizang block, and combined with the geological structures and seismic activities, some characteristics in regional tectonic deformation and strong earthquake development are studied and approached preliminarily. The results show that: a) The space-time distribution of current tectonic deformation in this area is inhomogeneous with relatively intensive tectonic deformation in the vicinity of main boundary faults and weak deformation in the farther areas. The intensity of vertical differential movement and the deformation status vary with time, and the horizontal movement and deformation are characterized by apparent compression and strike-slip. b) The tectonic stress field generated by the NE-trending continuous compressive movement of Qinghai-Xizang block due to the northward press and collision of India plate is the principal stress for the tectonic deformation and earthquake development in this area. The evolution of space-time distribution of tectonic deformation and seismicity is closely related to the block activity and dynamic evolution of regional tectonic stress field. c) The vertical deformation uplift and high-gradient deformation zones and the obvious fault deformation anomaly appeared along the boundaries of tectonic blocks can be considered as the indicators of hindered block motion and intensified tectonic stress field for strong earthquake development. Usually, the above-mentioned phenomena would be followed by the seismicity of M6.0, but the earthquake might not occur in the place with the maximum movement. The zones with the fault deformation anomaly characterized by tendencious accumulation acceleration turning and the surrounding areas might be the positions for accumulation of strain energy and development and occurrence of strong earthquakes.
