[1]WANG Yan,HONG Min,SHAO Desheng,et al.Study on Dynamic Characteristics of Crustal Deformation in Yunnan Area using GPS[J].Journal of Seismological Research,2018,41(03):368-374.
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Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
41
Number of periods:
2018 03
Page number:
368-374
Column:
Public date:
2018-08-20
- Title:
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Study on Dynamic Characteristics of Crustal Deformation in Yunnan Area using GPS
- Author(s):
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WANG Yan; HONG Min; SHAO Desheng; WANG Zhimin
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(Yunnan Earthquake Agency,Kunming 650224,Yunnan,China)
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- Keywords:
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least squares configuration; GPS velocity field; strain parameter; GPS velocity profile
- CLC:
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P315.725
- DOI:
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- Abstract:
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Based on the GPS velocity field data of 1999—2007 and 2011—2013,we used the least squares configuration method and GPS velocity profile results to synthetically analyze the dynamic evolution characteristics of crustal deformation in Yunnan area before and after the Wenchuan earthquake. The dynamic evolution of GPS velocity field shows that the direction is gradually changed from the south of the southern part of the Sichuan-Yunnan block to the south-west of the southern Yunnan block and there is a clear relative motion characteristic near the block boundary fault zone. Compared with the GPS velocity of 1999—2007,the results of 2011—2013 also reflect segmental deformation characteristics of the block boundary fault zone. South-east movement has a significant increase. This may be related to crustal deformation adjustment after the Wenchuan earthquake. The dynamic evolution of strain parameters shows that ‘middle tension,squeeze at both ends' is in the whole area and the distribution of deformation(shear,tension or extrusion)is closely related to the background motion and deformation characteristics of the main fault zone. Compared with results during the period of 1999—2007,the tensile zone in 2011—2013 has been expanded in the eastward and southward direction. The extrusion deformation of the eastern boundary(Xiaojiang fault zone)of the Sichuan-Yunnan block is no longer significant,mainly concentrated in the northern section of the Xiaojiang fault zone,which may be related to the post-seismic deformation adjustment of the Wenchuan earthquake. The GPS velocity profile results show that the left-lateral slip velocity of the Xiaojiang fault zone reduced gradually from north to south(from 10 mm/a to 5 mm/a),and the width of the northern section is wider. The right-hand slip rate of the Honghe fault zone is about 4 mm/a,and the deformation width is wider. The dynamic results show that the Wenchuan earthquake has little effect on the deformation modes of the two fault zones.