Study on the velocity structure of the crust in Southwest Yunnan of the north-south seismic belt—Results from the Menghai-Gengma-Lushui deep seismic sounding profile

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• 作者：ShuaiJun Wang ; BaoJin Liu ; JianShi Zhang ; BaoFeng Liu…
• 关键词：Southwest Yunnan ; seismic sounding profile ; crustal velocity structure ; fault
• 刊名：Science China Earth Sciences
• 出版年：2015
• 出版时间：December 2015
• 年：2015
• 卷：58
• 期：12
• 页码：2175-2187
• 全文大小：4,427 KB
• 参考文献：An M, Shi Y. 2006. Lithospheric thickness of the Chinese Continent. Phys Earth Planet Int, 159: 257-66CrossRef
  Bedrosian P A, Unsworth M J, Egbert G D. 2004. Geophysical images of the creeping segment of the San Andreas fault: Implications for the role of crustal fluids in the earthquake process. Tectonophysics, 385: 137-58CrossRef
  Bai Z M, Wang C Y. 2003. Tomographic investigation of the upper crustal structure and seismotectonic environments in Yunnan Province (in Chinese). Acta Seismol Sin, 25: 117-27
  Cerveny V. 2001. Seismic Ray Theory. Cambridge: Cambridge University PressCrossRef
  Cerveny V, Klimes L, Psencik I. 1988. Complete seismic-ray tracing in three-dimensional structures. In: Doornbos D J, ed. Seismological Algorithms. New York: Academic Press. 89-68
  Chen J, Hu J F, Yang H Y, Zhang X M, Wen L M, Peng H C. 2012. S-wave Q structure of the crust and uppermantle beneath Yunnan from surface waves. Sci China Earth Sci, 55: 858-68CrossRef
  Chen Y L, Niu F L, Liu R F, Huang Z B, Tkalcic H, Sun L. 2010. Crustal structure beneath China from receiver function analysis. J Geophys Res, 115: B03307, doi: 10.1029/2009JB006386
  Deng Q D, Xu X W, Yu G H. 1994. Subarea characteristics and genesis of active faults in continental China. In: Chinese Active Faults Research (in Chinese). Beijing: Seismol Press
  Deng Q D, Zhang P Z, Ran Y K, Yang X P, Min W, Chu Q Z. 2003. Basic characteristics of active tectonics of China. Science China Earth Science, 46: 356-72
  Ding Z F, Zeng R S. 1996. Observation and study of shear wave anisotropy in Tibetan plateau (in Chinese). Chin J Geophys, 39: 211-20
  Gao S, Davis P M, Liu H, Slack P D, Zorin Y A, Mordvinova V V, Kozhevnikov V M, Meyer R P. 1994. Seismic anisotropy and mantle flow beneath the Baikal rift zone. Nature, 71: 149-51CrossRef
  Gao X, Su Y, Wang W, Pei S P, Guo Z. 2009. Lower-crust S-wave velocity beneath western Yunnan Province from waveforrn inversion of dense seismic observations. Terra Nova, 21: 105-10CrossRef
  Hauksson E, Haase J. 1997. Three-dimensional Vp and Vp/Vs velocity models of the Los Angeles basin and central Transverse ranges, California. J Geophys Res, 102: 5423-453CrossRef
  Hickman S, Sibson R, Bruhn R. 1995. Introduction to special section: Mechanical involvement of fluids in faulting. J Geophys Res, 100: 1283l-2840
  Hirn A, Jiang M, Sapin M, Diaz J, Nercessian A, Lu Q T, Lepine J C, Shi D N, Sachpazi M, Pandey M R, Ma K Y, Gallart J. 1995. Seismic anisotropy as an indicator of mantle flow beneath the Himalayas and Tibet. Nature, 375: 571-74CrossRef
  Hu H X, Lu H X, Wang C Y, He Z Q, Zhu L B, Yan Q Z, Fan Y X, Zhang G Q, Deng Y E. 1986. Explosion investigation of the crustal structure in western Yunnan province (in Chinese). Chin J Geophys, 29: 133-44
  Huang J, Zhao D, Zheng S. 2002. Lithospheric structure and its relationship to seismic and volcanic activity in southwest China. J Geophys Res, 107: 2255, doi: 10.1029/2000JB000137CrossRef
  Huang R Q, Wang Z, Pei S P, Wang Y S. 2009. Crustal ductile flow and its contribution to tectonic stress in Southwest China. Tectonophysics, 473: 476-89CrossRef
  Jiang C S, Wang S J, Zhou R Q, Zhou Z H, Long X F, Wang Y. 2000. Dynamics study of tectonics on Tengchong volcano activity (in Chinese). Earthq Res, 23: 179-87
  Kan R J, Zhao J M. 1994. Crustal and mantle structure of Tengchong volcano area (in Chinese). In: Chen Y T, Kan R J, Teng J W. eds. Progress in Solid Geophysics of China. Beijing: China Ocean Press. 3-0
  Lei J S, Zhao D P, Su Y J. 2009. Insight into the origin of the Tengchong intraplate volcano and seismotectonics in southwest China from local and teleseismic data. J Geophys Res, 114: B05302, doi: 10.1029/2008JB005881
  Lei J S, Zhang G W, Xie F R, Li Y, Su Y J, Liu L F, Ma H H, Zhang J W. 2012. Relocation of the 10 March 2011 Yingjiang, China, earthquake sequence and its tectonic implications. Earthq Sci, 25: 103-10CrossRef
  Li C, van der Hilst R D, Meltzer A S, Engdahl E R. 2008. Subduction of the Indian lithosphere beneath the Tibetan Plateau and Burma. Earth Planet Sci Lett, 274: 157-68CrossRef
  Li F, Xu T, Wu Z B, Zhang Z J, Teng J W. 2013. Segmentally iterative ray tracing in 3-D heterogeneous geological models (in Chinese). Chin J Geophys, 56: 3512-522
  Li Y H, Wu Q J, Tian X B, Zhang R Q, Pan J T, Zeng R S. 2009. Crustal structure in the Yunnan region determined by modeling receiver functions (in Chinese). Chin J Geophys, 52: 67-0
  Lin Z Y, Hu H X, Zhang W B, Zhang H F, He Z Q, Lin Z M, Qiu T X. 1993. The investigation of velocity structure of the upper mantle in Yunnan region (in Chinese). Acta Seismol Sin, 5: 427-40
  Liu F T, Qu K X, Wu H, Li Q, Liu J H, Hu G. 1986. Seismic tomography of north China region (in Chinese). Chin J Geophys, 29: 442-49
  Lou H, Wang C Y. 2005. Wavelet analysis and interpretation of gravity data in Sichuan-Yunnan region (in Chinese). Acta Seismol Sin, 27: 515-23
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• 作者单位：ShuaiJun Wang (1)
  BaoJin Liu (1)
  JianShi Zhang (1)
  BaoFeng Liu (1)
  YuLing Duan (1)
  XiangHui Song (1)
  XiaoGuo Deng (1)
  CeJun Ma (1)
  YiRan Zang (1)
  
  1. Geophysical Exploration Center of China Earthquake Administration, Zhengzhou, 450002, China
  
• 刊物主题：Earth Sciences, general;
• 出版者：Springer Berlin Heidelberg
• ISSN：1869-1897

文摘

Southwest Yunnan, located in the southern segment of the north-south seismic belt, is one of the regions with strong tectonic movement and seismic activity in China. Study on the characteristics of tectonic setting and deep geophysical field in the region is an important issue in basic science. In 2013, we conducted a 600-km-long Menghai-Gengma-Lushui profile of deep seismic wide-angle reflection/refraction and high-resolution seismic refraction in Southwest Yunnan. In this paper, we use 6 groups of clear intracrustal P-wave phases picked from the seismic record sections of 11 shots to build a velocity structure model of basement and 2D crustal P-wave of the region by using finite difference inversion and ray travel time forward fitting technology. The results show that, from south to north, the crust gradually thickens along the profile and its basement shows a significant lateral heterogeneity. In the vicinity of the Nanting River fault, the basement structure shows the character of alternate depressions and uplifts, and the shallowest basement is about 1.0 km. In the vicinity of Tengchong and Lancang, the basement is about 5.0 km deep. The velocity of the middle and lower crust in the region generally increases with the increasing of depth. At the block boundary and beneath the fault tectonic belt, the velocity contours show apparent irregularity and the P-wave velocity changes sharply. In this region, the Moho gradually deepens from south to north with relatively large lateral undulations. The shallowest point of the Moho is located near Menghai at a depth of about 32.0 km. The deepest point of the Moho is located near Tengchong at a depth of about 40.5 km. Between Gengma and Yongde, the Moho shows significantly fast uplifting and depressing with an amplitude of about 4.0 km. Beneath the Nanting River fault, Longling-Ruili fault, Dayingjiang fault and Tengchong volcano, the basement velocity structure, 2D crustal P-wave velocity structure, distribution of average profile velocity and intracrustal interface spreading also show significant changes from the basement to the top of the Moho, indicating that the crustal velocity and medium physical properties beneath the fault tectonic belt are apparently different from the crustal materials on its both sides, which suggests that these faults should be in a certain scale and may extend to the lower crust or the top of the upper mantle. The earthquakes in the region mainly occurred at a depth of 10-0 km, and the seismic activity is related to the intracrustal medium velocity difference and fault belt distribution. The results can serve as the important data of the crust-mantle structure for the analysis of the deep tectonic setting, earthquake precise positioning, seismogenic structure modeling of the seismic activities in Southwest Yunnan, as well as the important reference for the evaluation of seismic hazard and the planning of earthquake disaster mitigation of this region. Keywords Southwest Yunnan seismic sounding profile crustal velocity structure fault