Geodynamic simulation of the WenChuan Ms8.0 and Lushan Ms7.0 earthquakes
|
摘要
The Lushan Ms7.0 earthquake, occurred on April 20th, 2013, is another strong earthquake that occurred on Longmen Mountain Faults after the Wenchuan Ms8.0 earthquake. In this paper we construct a finite element model depicting fault frictional mechanism to study the geodynamics of these two strong earthquakes. The locations of the initial rupture points and the dislocation forms of the Wenchuan earthquake and Lushan earthquake are simulated to find out the potential relationship between the two earthquakes. Simulative results show that the elevation, fault geometry, and the different rheological strengths between the Sichuan basin and Tibetan plateau play an important role in the earthquake dynamics. The dynamic simulation shows the initial rupture points are located at Yingxiu county and the rupture process is mainly along the northeast direction for the Wenchuan earthquake. In particular, the different frictional strengths caused by the fluid pressure decrease between the southern and northern segments of Longmenshan faults after the Wenchuan earthquake have affected the initial rupture point and the fault dislocation form of the Lushan earthquake, when considering the thrust of Tibetan plateau to Sichuan basin as the major dynamic source.
The Lushan Ms7.0 earthquake, occurred on April 20th, 2013, is another strong earthquake that occurred on Longmen Mountain Faults after the Wenchuan Ms8.0 earthquake. In this paper we construct a finite element model depicting fault frictional mechanism to study the geodynamics of these two strong earthquakes. The locations of the initial rupture points and the dislocation forms of the Wenchuan earthquake and Lushan earthquake are simulated to find out the potential relationship between the two earthquakes. Simulative results show that the elevation, fault geometry, and the different rheological strengths between the Sichuan basin and Tibetan plateau play an important role in the earthquake dynamics. The dynamic simulation shows the initial rupture points are located at Yingxiu county and the rupture process is mainly along the northeast direction for the Wenchuan earthquake. In particular, the different frictional strengths caused by the fluid pressure decrease between the southern and northern segments of Longmenshan faults after the Wenchuan earthquake have affected the initial rupture point and the fault dislocation form of the Lushan earthquake, when considering the thrust of Tibetan plateau to Sichuan basin as the major dynamic source.
The Lushan Ms7.0 earthquake, occurred on April 20th, 2013, is another strong earthquake that occurred on Longmen Mountain Faults after the Wenchuan Ms8.0 earthquake. In this paper we construct a finite element model depicting fault frictional mechanism to study the geodynamics of these two strong earthquakes. The locations of the initial rupture points and the dislocation forms of the Wenchuan earthquake and Lushan earthquake are simulated to find out the potential relationship between the two earthquakes. Simulative results show that the elevation, fault geometry, and the different rheological strengths between the Sichuan basin and Tibetan plateau play an important role in the earthquake dynamics. The dynamic simulation shows the initial rupture points are located at Yingxiu county and the rupture process is mainly along the northeast direction for the Wenchuan earthquake. In particular, the different frictional strengths caused by the fluid pressure decrease between the southern and northern segments of Longmenshan faults after the Wenchuan earthquake have affected the initial rupture point and the fault dislocation form of the Lushan earthquake, when considering the thrust of Tibetan plateau to Sichuan basin as the major dynamic source.
引文
[1] Y. Zhang, L.S. Xu, Y.T. Chen, Rupture process of the Lushan 4.20 earthquake and preliminary analysis on the disaster-causing mechanism, Chin. J. Geophys.56(4)(2013)1408-1411, https://doi.org/10.6038/cjg20130435(in Chinese).
[2] P.Z. Zhang, X.W. Xu, X.Z. Wen, Y.K. Ran, 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, Chin.J. Geophys. 51(4)(2008)1066-1073(in Chinese).
[3] B.Q. Ma, G. Su, Z.H. Hou, S.B. Shu, Late quaternary slip rate in the central part of the Longmenshan fault zone from terrace deformation along the Minjiang river, Seismol. Geol. 27(2)(2005)234-242(in Chinese).
[4] X. Xu, G. Chen, G. Yu, J. Cheng, X.B. Tan, A.L Zhu, X.Z. Wen, Seismogenic structure of Lushan earthquake and its relationship with Wenchuan earthquake, Earth Sci. Front. 20(3)(2013)011-020(in Chinese),
[5] Y.T. Chen, Z.X. Yang, Y. Zhang, C. Liu, From 2008 Wenchuan earthquake to 2013Lushan earthquake, Scientia Sinica Terrae 43(2013)1064-1072(in Chinese).
[6] H. Wang, M. Liu, X.H. Shen, J. Liu, Balance of seismic moment in the SongpanGanze region, eastern Tibet:implications for the 2008 Great Wenchuan earthquake, Tectonophysics 491(2010)154-164.
[7] B. Shan, X. Xiong, Y. Zheng, F.Q. Diao, Stress changes on major faults caused by Mw7.9 Wenchuan earthquake, May 12,2008, Sci. China Ser. D Earth Sci. 52(5)(2009)593-601, https://doi.org/10.1007/s11430-009-0060-9.
[8] Y.Z. Wang, F. Wang, M. Wang, Z.K. Shen, Y. Wan, Coulomb stress change and evolution induced by the 2008 Wenchuan earthquake and its delayed triggering of the 2013 Mw 6.6 Lushan earthquake, Seismol. Res. Lett. 85(1)(2014)52-59.
[9] X.L Lei, S.L. Ma, J.R. Su, X.L. Wang, Inelastic triggering of the 2013 m_w 6. 6lushan earthquake by the 2008 m_w 7. 9 wenchuan earthquake, Seismol.Geol. 35(2)(2013)411-422(in Chinese).
[10] G. Luo, M. Liu, Stress evolution and fault interactions before and after the 2008Great Wenchuan earthquake, Tectonophysics 491(1)(2010)127-140.
[11] J. Song, Y. Zhou, Effect of the fluid to fault strength and strong earthquake gestation, Recent Dev. World Seismol. 420(2013)5-16(in Chinese).
[12] Y.S. Zhou, C.R. He, The rheological structures of crust and mechanics of highangle reverse fault slip for Wenchuan MS8.0 earthquake, Chin. J.Geophys. 52(2)(2009)474-484(in Chinese).
[13] P. Bird, X. Kong, Computer simulations of California tectonics confirm very low strength of major faults, Geol. Soc. Am. Bull. 106(2)(1994)159-174.
[14] X. Kong, P. Bird, SHELLS:a thin-shell program for modeling neotectonics of regional or global lithosphere with faults, J. Geophys. Res. 100(1995)22129-22131.
[15] P. Bird, Thin-plate and thin-shell finite-element programs for forward dynamic modeling of plate deformation and faulting, Comput. Geosci. 25(4)(1999)383-394.
[16] Q.D. Deng, P.Z. Zhang, Y.K. Ran, X.P. Yang, M. Wang, L.C. Chen, Active tectonics and earthquake activities in China, Earth Sci. Front. 10(A)(2003)66-73(in Chinese).
[17] Y. Wang, J.Y. Wang, Terrestrial heat flow pattern and thermo-tectonic domains in the continental area of China, J. Grad. Sch. Chin. Acad. Sci. 18(1)(2001)51-58(in Chinese).
[18] C.Y. Wang, W.D. Mooney, X.L Wang, J.P. Wu, H. Lou, F. Wang, A study on 3-D velocity structure of crust and upper mantle in Sichuan-Yunnan region, China,Earthq. Sci. 15(1)(2002)1-17(in Chinese).
[19] J. Huang, X.D. Song, S.Y. Wang, Pn velocity structure of uppermost mantle beneath Sichuan-Yunnan region and continent dynamics implication, Sci.China 33(suppl)(2003)144-151(in Chinese).
[20] J.P. Wu, Y.H. Ming, C.Y. Wang, Regional waveform inversion for crustal and upper mantle velocity structure below Chuandian regio, Chin. J.Geophys. 49(5)(2006)1369-1376(in Chinese).
[21] L Liao, D.N. Zhang, J.S. Yang, Numerical simulation of 5.12 Wenchuan MS8.0earthquake geodynamic background, Chin. J. Geophys. 55(1)(2012)126-136.https://doi.Org/10.6038/j.issn.0001-5733.2012.01.012(in Chinese).
[22] H. Yasuhara, C. Marone, D. Elsworth, Fault zone restrengthening and frictional healing:the role of pressure solution, J. Geophys. Res. 110(2005)B06310,https://doi.org/10.1029/2004JB003327.
[23] Y.G. Li, J.E. Vidale, S.M. Day, D.D. Oglesby, E. Cochran, Post-seismic fault healing on the rupture zone of the 1999 M7.1 Hector Mine, California earthquake, Bull. Seismol. Soc. Am. 93(2)(2003)854-869.
[24] P.Z. Zhang, Z.K. Shen, M. Wang, W.J. Gan, Kinematics of present-day tectonic deformation of the Tibetan plateau and its vicinities, Seismol. Geol. 26(3)(2004)367-377(in Chinese).
[26] Y. Zhang, LS. Xu, Y.T. Chen, Spatio-temporal variation of the source mechanism of the 2008 great Wenchuan earthquake, Chin. J. Geophys. 52(2)(2009)379-389(in Chinese).
[2] P.Z. Zhang, X.W. Xu, X.Z. Wen, Y.K. Ran, 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, Chin.J. Geophys. 51(4)(2008)1066-1073(in Chinese).
[3] B.Q. Ma, G. Su, Z.H. Hou, S.B. Shu, Late quaternary slip rate in the central part of the Longmenshan fault zone from terrace deformation along the Minjiang river, Seismol. Geol. 27(2)(2005)234-242(in Chinese).
[4] X. Xu, G. Chen, G. Yu, J. Cheng, X.B. Tan, A.L Zhu, X.Z. Wen, Seismogenic structure of Lushan earthquake and its relationship with Wenchuan earthquake, Earth Sci. Front. 20(3)(2013)011-020(in Chinese),
[5] Y.T. Chen, Z.X. Yang, Y. Zhang, C. Liu, From 2008 Wenchuan earthquake to 2013Lushan earthquake, Scientia Sinica Terrae 43(2013)1064-1072(in Chinese).
[6] H. Wang, M. Liu, X.H. Shen, J. Liu, Balance of seismic moment in the SongpanGanze region, eastern Tibet:implications for the 2008 Great Wenchuan earthquake, Tectonophysics 491(2010)154-164.
[7] B. Shan, X. Xiong, Y. Zheng, F.Q. Diao, Stress changes on major faults caused by Mw7.9 Wenchuan earthquake, May 12,2008, Sci. China Ser. D Earth Sci. 52(5)(2009)593-601, https://doi.org/10.1007/s11430-009-0060-9.
[8] Y.Z. Wang, F. Wang, M. Wang, Z.K. Shen, Y. Wan, Coulomb stress change and evolution induced by the 2008 Wenchuan earthquake and its delayed triggering of the 2013 Mw 6.6 Lushan earthquake, Seismol. Res. Lett. 85(1)(2014)52-59.
[9] X.L Lei, S.L. Ma, J.R. Su, X.L. Wang, Inelastic triggering of the 2013 m_w 6. 6lushan earthquake by the 2008 m_w 7. 9 wenchuan earthquake, Seismol.Geol. 35(2)(2013)411-422(in Chinese).
[10] G. Luo, M. Liu, Stress evolution and fault interactions before and after the 2008Great Wenchuan earthquake, Tectonophysics 491(1)(2010)127-140.
[11] J. Song, Y. Zhou, Effect of the fluid to fault strength and strong earthquake gestation, Recent Dev. World Seismol. 420(2013)5-16(in Chinese).
[12] Y.S. Zhou, C.R. He, The rheological structures of crust and mechanics of highangle reverse fault slip for Wenchuan MS8.0 earthquake, Chin. J.Geophys. 52(2)(2009)474-484(in Chinese).
[13] P. Bird, X. Kong, Computer simulations of California tectonics confirm very low strength of major faults, Geol. Soc. Am. Bull. 106(2)(1994)159-174.
[14] X. Kong, P. Bird, SHELLS:a thin-shell program for modeling neotectonics of regional or global lithosphere with faults, J. Geophys. Res. 100(1995)22129-22131.
[15] P. Bird, Thin-plate and thin-shell finite-element programs for forward dynamic modeling of plate deformation and faulting, Comput. Geosci. 25(4)(1999)383-394.
[16] Q.D. Deng, P.Z. Zhang, Y.K. Ran, X.P. Yang, M. Wang, L.C. Chen, Active tectonics and earthquake activities in China, Earth Sci. Front. 10(A)(2003)66-73(in Chinese).
[17] Y. Wang, J.Y. Wang, Terrestrial heat flow pattern and thermo-tectonic domains in the continental area of China, J. Grad. Sch. Chin. Acad. Sci. 18(1)(2001)51-58(in Chinese).
[18] C.Y. Wang, W.D. Mooney, X.L Wang, J.P. Wu, H. Lou, F. Wang, A study on 3-D velocity structure of crust and upper mantle in Sichuan-Yunnan region, China,Earthq. Sci. 15(1)(2002)1-17(in Chinese).
[19] J. Huang, X.D. Song, S.Y. Wang, Pn velocity structure of uppermost mantle beneath Sichuan-Yunnan region and continent dynamics implication, Sci.China 33(suppl)(2003)144-151(in Chinese).
[20] J.P. Wu, Y.H. Ming, C.Y. Wang, Regional waveform inversion for crustal and upper mantle velocity structure below Chuandian regio, Chin. J.Geophys. 49(5)(2006)1369-1376(in Chinese).
[21] L Liao, D.N. Zhang, J.S. Yang, Numerical simulation of 5.12 Wenchuan MS8.0earthquake geodynamic background, Chin. J. Geophys. 55(1)(2012)126-136.https://doi.Org/10.6038/j.issn.0001-5733.2012.01.012(in Chinese).
[22] H. Yasuhara, C. Marone, D. Elsworth, Fault zone restrengthening and frictional healing:the role of pressure solution, J. Geophys. Res. 110(2005)B06310,https://doi.org/10.1029/2004JB003327.
[23] Y.G. Li, J.E. Vidale, S.M. Day, D.D. Oglesby, E. Cochran, Post-seismic fault healing on the rupture zone of the 1999 M7.1 Hector Mine, California earthquake, Bull. Seismol. Soc. Am. 93(2)(2003)854-869.
[24] P.Z. Zhang, Z.K. Shen, M. Wang, W.J. Gan, Kinematics of present-day tectonic deformation of the Tibetan plateau and its vicinities, Seismol. Geol. 26(3)(2004)367-377(in Chinese).
[26] Y. Zhang, LS. Xu, Y.T. Chen, Spatio-temporal variation of the source mechanism of the 2008 great Wenchuan earthquake, Chin. J. Geophys. 52(2)(2009)379-389(in Chinese).