Numerical analysis of contemporary horizontal tectonic deformation fields in China from GPS data

Assuming that the contemporary tectonic activity in China can be treated as continuous, we have simulated 1 245 present-day multiple-epoch GPS velocity solutions in the range of Chinese mainland, Mongolia, Myanma, India, Nepal and Himalayas with a bi-cubic spline interpolation function to inverse the integral horizontal velocity with the fitting accuracy less than 3 mm and obtained the strain rate fields in Chinese mainland. We have also analyzed the characteristics of spatial distribution of horizontal deformation and strain rate fields in Chinese mainland. The result shows that the analysis on the continuous deformation in the large-scale and dense GPS velocity fields can reveal not only the integral tectonic characters of Chinese mainland but also the tectonic characters in local regions. Generally, the magnitude and intensity of horizontal tectonic deformation have a mutation in the South-North Seismic Belt (95°E–102°E), which is stronger in the west than the east and stronger in the south than the north. Large strain rates are found in the areas as Kunlun block, Xianshuihe fault zone and central Yunnan, and the variation of velocity is very rapid. At the same time, the tectonic activity is relatively calm on Altyn Tagh fault zone, and extensive strain is found in the eastern part of central Tianshan.

[1]  G. Peltzer,et al.  Magnitude of Late Quaternary Left-Lateral Displacements Along the North Edge of Tibet , 1989, Science.

[2]  Mathilde Vergnolle,et al.  GPS measurements of crustal deformation in the Baikal‐Mongolia area (1994–2002): Implications for current kinematics of Asia , 2003 .

[3]  W. Holt,et al.  Earthquake strain rates and instantaneous relative motions within central and eastern Asia , 1995 .

[4]  X. Pichon,et al.  Velocity field in Asia inferred from Quaternary fault slip rates and Global Positioning System observations , 2000 .

[5]  Roland Bürgmann,et al.  Convergence across the northwest Himalaya from GPS measurements , 2002 .

[6]  Jin Ma,et al.  Active tectonic blocks and strong earthquakes in the continent of China , 2003, Science in China Series D Earth Sciences.

[7]  Peter Molnar,et al.  Active deformation of Asia : From kinematics to dynamics , 1997 .

[8]  Zheng‐Kang Shen,et al.  Contemporary crustal deformation of the Chinese continent and tectonic block model , 2003 .

[9]  Zhong-huai Xu.  A present-day tectonic stress map for eastern Asia region , 2001 .

[10]  M. Bouin,et al.  Present-day crustal deformation around Sagaing fault, Myanmar , 2003 .

[11]  Peter Molnar,et al.  The field of crustal velocity in Asia calculated from Quaternary rates of slip on faults , 1997 .

[12]  W. Holt,et al.  A procedure for obtaining the complete horizontal motions within zones of distributed deformation from the inversion of strain rate data , 1993 .

[13]  G. Peltzer,et al.  Present‐day kinematics of Asia derived from geologic fault rates , 1996 .

[14]  James Jackson,et al.  The accommodation of Arabia‐Eurasia Plate convergence in Iran , 1995 .

[15]  Danan Dong,et al.  Crustal deformation along the Altyn Tagh Fault system , 2001 .

[16]  M. Zoback.  First‐ and second‐order patterns of stress in the lithosphere: The World Stress Map Project , 1992 .

[17]  Jing-nan Liu,et al.  Present-Day Crustal Deformation in China Constrained by Global Positioning System Measurements , 2001, Science.

[18]  R. Bürgmann,et al.  The motion and active deformation of India , 2001 .

[19]  P. Molnar,et al.  Fault plane solutions of earthquakes and active tectonics of the Tibetan Plateau and its margins , 1989 .