Abstract
We relocated M8.0 Wenchuan earthquake and 2706 aftershocks with M⩾2.0 using double-difference algorithm and obtained relocations of 2553 events. To reduce the influence of lateral variation in crustal and upper mantle velocity structure, we used different velocity models for the east and west side of Longmenshan fault zone. In the relocation process, we added seismic data from portable seismic stations close to the shocks to constrain focal depths. The precisions in E-W, N-S, and U-D directions after relocation are 0.6, 0.7, and 2.5 km respectively. The relocation results show that the aftershock epi-centers of Wenchuan earthquake were distributed in NE-SW direction, with a total length of about 330 km. The aftershocks were concentrated on the west side of the central fault of Longmenshan fault zone, excluding those on the north of Qingchuan, which obviously deviated from the surface fault and passed through Pingwu-Qingchuan fault in the north. The dominant focal depths of the aftershocks are between 5 and 20 km, the average depth is 13.3 km, and the depth of the relocated main shock is 16.0 km. The depth profile reveals that focal depth distribution in some of the areas is characterized by high-angle westward dipping. The rupture mode of the main shock features reverse faulting in the south, with a large strike-slip component in the north.
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References
Bai L X, Wen X Z. Seismic potential of long-term strong shock on the Maowen-Wenchuan segment of the Longmenshan fault zone (in Chinese). Earthqu Res Sichuan, 1994, 3: 51–58
Deng Q D, Chen S F, Zhao X L. Tectonics, seismicity and dynamics of Longmenshan mountains and its adjacent regions (in Chinese). Seismol Geol, 1994, 16(4): 389–403
Wang E Q, Meng Q R, Chen Z, et al. Early Mesozoic left-lateral movement along the Longmenshan fault belt and its tectonic implications (in Chinese). Earth Sci Front, 2001, 8(2): 375–384
Xu X W, Zhang P Z, Wen X Z, et al. Features of active tectonics and recurrence behaviors of strong earthquakes in the western Sichuan Province and its adjacent regions (in Chinese). Seismol Geol, 2005, 27(3): 446–461
Cheng G G, Ji F J, Zhou R J, et al. Primary research of activity segmentation of Longmenshan fault zone since late Quaternary (in Chinese). Seismol Geol, 2007, 29(3): 657–673
Li C Y, Song F M, Ran Y K. Late Quaternary activity and age constraint of the northern Longmenshan fault zone (in Chinese). Seismol Geol, 2004, 26(2): 248–258
Zhang Y, Feng W P, Xu L S, et al. The rupture process of 2008 Wenchuan earthquake in time and space scale. Sci China Ser D-Earth Sci, 2008, doi: 10.1007/s11430-008-0148-7
Wang C Y, Wu J P, Lou H, et al. P-wave crustal velocity structure in western Sichuan and eastern Tibetan region. Sci China Ser D-Earth Sci, 2003, 46(Suppl.): 254–265
Waldhauser F, Ellsworth W L. A double-difference earthquake location algorithm: Method and application to the Northern Hayward Fault, California. Bull Seismol Soc Amer, 2000, 90(6): 1353–1368
Waldhauser F, Ellsworth W L. Fault structure and mechanics of the Hayward Fault, California, from double-difference earthquake locations. J Geophys Res, 2002, 107(B3), doi: 10.1029/2000JB000084
Schaff D P, Richard P G. Repeating seismic events in China. Science, 2004, 303: 1176–1178
Hauksson E, Shearer P. Southern California hypocenter relocation with waveform cross-correlation, Part 1: Results using the doubledifference method. Bull Seismol Soc Amer, 2005, 95(3): 896–903
Got J L, Freche T J, Klein F W. Deep fault plane geometry inferred from multiplet relative relocation beneath the south flank of Kilauca. J Geophys Res, 1994, 99: 15375–15386
Huang Y, Yang J S, Zhang T Z. Relocation of the Bachu-Jiashi, Xinjiang earthquake sequence in 2003 using the double-difference location algorithm (in Chinese). Chinese J Geophys, 2006, 49(1): 162–169
Zhang T Z, Wu Bater, Huang Y, et al. Effect of the data recorded at nearby stations on earthquake relative location (in Chinese). Chinese J Geophys, 2007, 50(4): 1123–1130
Zhao Z, Cheng N. Accuracy amendment of focal location along the Longmenshan fault in the north of Sichuan (in Chinese). Earthqu Res Sichuan, 1995, 4: 19–30
Zhang Z J, Li Y K, Wang G J, et al. East-west crustal structure and “down-bowing” Moho under the northern Tibet revealed by wide-angle seismic profile. Sci China Ser D-Earth Sci, 2002, 45(6): 550–558
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(6): 615–622
Peng F N, Ye Y C. Seismogenic fault of the 1999 Chi-Chi earthquake in Taiwan Province and the features of earthquake damages (in Chinese). Seismol Geol, 2004, 26(4): 576–585
Yang Z X, Chen Y T, Zheng Y J, et al. Accurate relocation of earthquakes in central-western China using the double-difference earthquake location algorithm. Sci China Ser D-Earth Sci, 2003, 46(Suppl.): 181–188
Hu X L, Diao G L, Gao J C. Some evidences for earthquake occurrence in the shallow crust in some areas of North China and southwest China (in Chinese). Acta Seismol Sin, 2001, 23(4): 427–435
Chien H C, Yih M W, Tzay C, et al. Relocation of the 1999 Chi-Chi Earthquake in Taiwan. TAO, 2000, 11(3): 581–590
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Supported by the Basic Research Project of Institute of Geophysics, China Earthquake Administration (Grant No. DQJB08Z03)
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Huang, Y., Wu, J., Zhang, T. et al. Relocation of the M8.0 Wenchuan earthquake and its aftershock sequence. Sci. China Ser. D-Earth Sci. 51, 1703–1711 (2008). https://doi.org/10.1007/s11430-008-0135-z
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DOI: https://doi.org/10.1007/s11430-008-0135-z