Abstract
The mainshock of April 20, 2013 Sichuan Lushan M S7.0 earthquake was relocated using a 3-D velocity model. Double difference algorithm was applied to relocate aftershock sequences of Lushan earthquake. The locations of 2405 aftershocks were determined. The location errors in E-W, N-S and U-D direction were 0.30, 0.29 and 0.59 km on average, respectively. The location of the mainshock is 102.983°E, 30.291°N and the focal depth is 17.6 km. The relocation results show that the aftershocks spread approximately 35 km in length and 16 km in width. The dominant distribution of the focal depth ranges from 10 to 20 km. A few earthquakes occurred in the shallow crust. Focal depth profiles show fault planes dip to the northwest, manifested itself as a listric thrust fault. The dip angle is steep in the shallow crust and gentle in the deep crust. Although the epicenters of aftershocks distributed mainly along both sides of the Shuangshi-Dachuan fault, the seismogenic fault may be a blind thrust fault on the eastern side of the Shuangshi-Dachuan fault. Earthquake relocation results reveal that there is a southeastward tilt aftershock belt intersecting with the seismogenic fault with y-shape. We speculate it is a back thrust fault that often appears in a thrust fault system. Lushan earthquake triggered the seismic activity of the back thrust fault.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Liu J, Yi G X, Zhang Z W, et al. Introduction to the Lushan, Sichuan M7.0 earthquake on 20 April 2013 (in Chinese). Chin J Geophys, 2013, 56: 1404–1407
Tang R C, Han W B. Active Faults and Earthquakes in Sichuan (in Chinese). Beijing: Seismological Press, 1993. 1–368
Deng Q D, Chen S F, Zhao X L. Tectonics, seismicity and dynamics of Longmenshan mountains and its adjacent regions (in Chinese). Seism Geol, 1994, 16: 389–403
Zhang P Z, Wen X Z, Xu X W, et al. Tectonic model of the great Wenchuan earthquake of May 12, 2008, Sichuan, China (in Chinese). Chin Sci Bull (Chin Ver), 2009, 54: 944–953
Zhang P Z, Xu X W, Wen X Z, et al. Slip rates and recurrence intervals of the Longmen Shan active fault zone, and tectonic implications for the mechanism of the May 12 Wenchuan earthquake, 2008, Sichuan, China (in Chinese). Chin J Geophys, 2008, 51: 1066–1073
Jia D, Chen Z X, Jia C Z, et al. Longmen Shan foreland fold and thrust belt of the western Sichuan foreland basin development (in Chinese). Geol J Chin Univ, 2003, 9: 402–409
Xu X W, Zhang P Z, Wen X Z, et al. Western Sichuan and its neighboring regions active tectonics and earthquake recurrence model (in Chinese). Seism Geol, 2005, 27: 446–461
Chen G G, Ji F J, Zhou R J, et al. Longmen Shan fault zone late Quaternary activity segmentation preliminary study (in Chinese). Seism Geol, 2007, 29: 657–673
Liu Q Y, Li Y, Chen J H, et al. Wenchuan M S8.0 earthquake: Preliminary study of the S-wave velocity structure of the crust and upper mantle (in Chinese). Chin J Geophys, 2009, 52: 309–319
Wen X Z, Zhang P Z, Du F, et al. The background of historical and modern seismic activities of the occurrence of the 2008 M S8.0 Wenchuan, Sichuan, earthquake (in Chinese). Chin J Geophys, 2009, 52: 444–454
Zhou S Y. Seismicity simulation in Western Sichuan of China based on the fault interactions and its implication on the estimation of the regional earthquake risk (in Chinese). Chin J Geophys, 2008, 51: 165–174
Lei J S, Zhao D P, Su J R, et al. Fine seismic structure under the Longmenshan fault zone and the mechanism of the large Wenchuan earthquake (in Chinese). Chin J Geophys, 2009, 52: 339–345
Xu X W, Han Z J, Li C Y, et al. Lushan M S7.0 earthquake: A blind reserve-fault earthquake. Chin Sci Bull, 2013, 58: 3437–3443
Zheng X F, Ouyang B, Zhang D N, et al. Technical system construction of Data Backup Centre for China Seismograph Network and the data support to researches on the Wenchuan earthquake (in Chinese). Chin J Geophys, 2009, 52: 1412–1417
Wu J P, Huang Y, Zhang T Z, et al. Aftershock distribution of the M S8.0 Wenchuan earthquake and three dimensional P-wave velocity structure in and around source region (in Chinese). Chin J Geophys, 2009, 52: 320–328
Fang L H, Wu J P, Zhang T Z, et al. 2011 Yunnan Yingjiang M S5.8 earthquake and its aftershock sequence relocations (in Chinese). Acta Seismol Sin, 2011, 33: 262–267
Wang C Y, Han W B, Wu J P, et al. Crustal structure beneath the eastern margin of the Tibetan Plateau and its tectonic implications. J Geophys Res, 2007, 112: B07307
Zhao Z, Fan J, Zheng S H, et al. Crustal structure and accurate hypocenter determination along the Longmenshan Fault zone (in Chinese). Acta Seismol Sin, 1997, 19: 615–622
Wang C Y, Lou H, Yao Z X, et al. Crustal thicknesses and poisson’s ratios in Longmenshan mountains and adjacent regions (in Chinese). Quat Sci, 2010, 30: 652–661
Waldhauser F, Ellsworth W L. A double-difference earthquake location algorithm: Method and application to the Northern Hayward Fault, California. Bull Seismol Soc Am, 2000, 90: 1353–1368
Yang Z X, Chen Y T, Zheng Y J, et al. Double-difference earthquake location method in our Midwest earthquake precise positioning ap plication (in Chinese). Sci China Ser D-Earth Sci, 2003, 33(Suppl.): 129–134
Yu X W, Chen Y T, Wang P D. Three-dimensional P-wave velocity structure in Beijing-Tianjin-Tangshan area (in Chinese). Acta Seismol Sin, 2003, 25: 1–14
Zhu A L, Xu X W, Zhou Y S, et al. Relocation of small earthquakes in western Sichuan, China and its implications for active tectonics (in Chinese). Chin J Geophys, 2005, 48: 629–636
Huang Y, Wu J P, Zhang T Z, et al. Wenchuan 8.0 earthquake and its aftershocks relocation. Sci China Ser D-Earth Sci, 2008, 38: 1242–1249
Chen H L, Zhao C P, Xiu J G, et al. Study on precise relocation of Longtan reservoir earthquakes and its seismic activity (in Chinese). Chin J Geophys, 2009, 52: 2035–2043
Zheng Y, Ma H S, Lu J, et al. Source mechanism of strong aftershocks (M S≥5.6) of Wenchuan earthquake and the implication for seismotectonic (in Chinese). Sci China Ser D-Earth Sci, 2009, 39: 413–426
Chen J H, Liu Q Y, Li S C, et al. Seismotectonic study by relocation of the Wenchuan M S8.0 earthquake sequence (in Chinese). Chin J Geophys, 2009, 52: 390–397
Monitoring and Prediction Division, China Earthquake Administration. Wenchuan 8.0 Earthquake Research Reports (in Chinese). Beijing: Seismological Press, 2009. 1–216
Zhang Y, Xu L S, Chen Y T. Rupture process of the Lushan 4.20 earthquake and preliminary analysis on the disaster-causing mechanism (in Chinese). Chin J Geophys, 2013, 56: 1408–1411
Zhu Z C. Structural Geology (in Chinese). Beijing: China University of Geosciences Press, 1999. 1–273
Suppe J. Principles of Structural Geology. J Struct Geol, 1985, 8: 1–721
Jin W Z, Tang L J, Yang K M, et al. Deformation and zonation of the Longmenshan fold and thrust zone in the western Sichuan basin (in Chinese). Acta Geol Sin, 2007, 81: 1072–1080
Luo Q. Characteristics of faults in Majiatan area of west Ordos basin and their petroleum reservoir controlling model (in Chinese). Acta Geos Sin, 2008, 29: 619–627
Xu Z Q, Li H Q, Hou L W, et al. Uplift of the Longmen-Jinping orogenic belt along the eastern margin of the Qinghai-Tibet Plateau: Large-scale detachment faulting and extrusion mechanism (in Chinese). Geol Bull China, 2007, 26: 1262–1276
Liu S W, Yang K, Li Q G, et al. Petrogenesis of the Neoproterozoic Baoxing Complex and its constraint on the tectonic environment in western margin of Yangtze Craton (in Chinese). Earth Sci Front, 2009, 16: 107–118
Chien H C, Yih M W, Tzay C S, et al. Relocation of the 1999 Chi-Chi Earthquake in Taiwan. Terr Atmos Oceanic Sci, 2000, 11: 581–590
Tao W, Hu C B, Wan Y G, et al. Dynamic modeling of thrust earthquake on listric fault and its inference to study of Wenchuan earthquake (in Chinese). Chin J Geophys, 2011, 54: 1260–1269
Author information
Authors and Affiliations
Corresponding author
Additional information
This article is published with open access at Springerlink.com
Rights and permissions
This article is published under an open access license. Please check the 'Copyright Information' section either on this page or in the PDF for details of this license and what re-use is permitted. If your intended use exceeds what is permitted by the license or if you are unable to locate the licence and re-use information, please contact the Rights and Permissions team.
About this article
Cite this article
Fang, L., Wu, J., Wang, W. et al. Relocation of the mainshock and aftershock sequences of M S7.0 Sichuan Lushan earthquake. Chin. Sci. Bull. 58, 3451–3459 (2013). https://doi.org/10.1007/s11434-013-6000-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11434-013-6000-2