SEISMOGENIC STRUCTURE AND RUPTURE MECHANISM OF THE MS 8.0 WENCHUAN EARTHQUAKE

doi:10.3969/j.issn.0253-4967.2012.04.003

Abstract

Abstract:

A composite multiple seismogenic source model is presented to interpret the preparation and generation of the Wenchuan earthquake,based on the results of investigations on the coseismic surface rupture,aftershock distribution and crustal deformation of the Wenchuan earthquake and the studies on the tectonic deformation conducted before the earthquake. It is assumed that the differences in the structure and property of the lithosphere beneath the west Sichuan plateau,Longmen Shan and Sichuan Basin led to the differences in deformation behavior and stress accumulation between them,and their joint actions resulted in the high accumulation and abrupt release of stress in the Longmen Shan Fault zone,witch eventually generated the Wenchuan mega-earthquake. As a high-friction high-angle listric thrust,the Longmen Shan Fault zone is not liable to deformation(but high stress accumulation)to form "slip deficit zones" before earthquake,or to micro-rupturing to form "seismic gaps" before earthquake. When stress accumulated exceeded the strength of the Longmen Shan Fault zone,burst occurred,creating the huge earthquake. Coseismic deformation and energy release were concentrated mainly in the Longmen Shan Fault zone to offset the pre-earthquake "slip deficit" and "seismic gap".The high-angle listric thrust structure of the seismogenic fault of the Wenchuan earthquake played an important role in controlling the preparation and generation of the Wenchuan earthquake. The decrease of normal stress resulting from increased displacement rate on the fault plane was the major contributor to the rupture of the high-angle listric thrust fault.

Key words: Wenchuan earthquake, Seismogenic fault, rupture process

摘要：

通过对汶川地震同震地表破裂、余震分布、地壳形变等的考察以及震前构造变形的研究,提出了汶川地震孕育和发生的多单元组合模型,认为川西高原、龙门山和四川盆地岩石圈结构及性质的差异造成了它们在变形方式和应力积累上的差异,其共同作用导致了龙门山断裂带应力的高度积累和突发释放,形成了汶川特大地震。龙门山断裂带具有高摩擦强度和高角度铲型逆冲结构,使得其不仅不易发生变形(但能积累很高的应力)形成震前的 "滑动亏损带",而且不易发生微破裂形成震前的 "地震空区"。当应力积累超过龙门山断裂带的强度时,就突发破裂形成巨大地震,同震变形和能量释放主要发生在龙门山断裂带,补偿震前的 "滑动亏损"、填满震前的 "地震空区"。汶川地震发震断裂的高角度铲型逆冲结构对于汶川地震的孕育和发生起着重要的控制作用,断裂面上位移加速导致的正应力下降是高角度铲型逆冲断裂发生破裂的重要原因。

关键词: 汶川地震, 发震构造, 破裂机理

CLC Number:

P315.2

ZHANG Pei-zhen, ZHU Shou-biao, ZHANG Zhu-qi, WANG Qing-liang. SEISMOGENIC STRUCTURE AND RUPTURE MECHANISM OF THE M_S 8.0 WENCHUAN EARTHQUAKE[J]. SEISMOLOGY AND GEOLOGY, 2012, (4): 566-575.

张培震, 朱守彪, 张竹琪, 王庆良. 汶川地震的发震构造与破裂机理[J]. 地震地质, 2012, (4): 566-575.

References

徐锡伟,闻学泽,叶建青,等.2008.汶川M_S 8.0地震地表破裂带及其发震构造［J］.地震地质,30(3): 597-629.
XU Xi-wei,WEN Xue-ze,YE Jian-qing,et al.2008.The M_S8.0 Wenchuan earthquake surface ruptures and its seismogenic structure ［J］.Seismology and Geology,30(3): 597-629(in Chinese).
张培震,闻学泽,徐锡伟,等.2009.2008年汶川8.0级特大地震孕育和发生的多单元组合模式［J］.科学通报,54(7): 944-953.
ZHANG Pei-zhen,WEN Xue-ze,XU Xi-wei,et al.2009.Tectonic model of the great Wenchuan earthquake of May 12,2008,Sichuan,China ［J］.Chinese Sci Bull,54(7): 944-953(in Chinese).
Avouac J P.2003.Mountain building,erosion,and the seismic cycle in the Nepal Himalaya ［J］.Adv Geophys,46:11-80.doi: 10.1016/S0065-2687(03)46001-9.
Burchfiel B C,Royden L H,van der Hilst R D,et al.2008.A geological and geophysical context for the Wenchuan earthquake of 12 May 2008,Sichuan,People's Republic of China ［J］.GSA Today, 18(7): 4-11.doi: 10.1130/GSATG18A.1
Chen J,Liu Q,Li S, et al. 2009. Seismotectonics study by relocation of the Wenchuan M_S 8.0 earthquake sequence ［J］.Chinese J Geophys,52: 390-397(in Chinese).
Densemore A L,Ellis M,Li Y,et al.2007.Active tectonics of the Beichuan and Pengguan Faults at the eastern margin of the Tibetan Plateau ［J］.Tectonics,26: TC4005.doi: 10.1029/2006TC001987.
Feldl N,Bilham R.2006.Great Himalayan earthquakes and the Tibetan Plateau ［J］.Nature,444: 165-170.doi: 10.1038/nature05199.
Li S,Lai X,Yao Z,et al.2009.Study on fault zone structures of northern and southern portions of the main central fault generated by M_S=8.0 Wenchuan earthquake using fault zone trapped waves ［J］.Acta Seismologica Sinica,22: 417-424.
Liu Zeng J,Zhang Z,Wen L,et al.2009.Co-seismic ruptures of the 12 May 2008,M_S 8.0 Wenchuan earthquake,Sichuan: East-west crustal shortening on oblique,parallel thrusts along the eastern edge of Tibet ［J］.Earth Planet Sci Lett,286: 355-370.
Scholtz C H.1990.The Mechanics of Earthquakes and Faulting ［M］.Cambridge Univ Press.
Scholz C H.1998.Earthquakes and friction laws ［J］.Nature,391(1): 36-42.
Shen Z K,Lü J N,Wang M,et al.2005.Contemporary crustal deformation around the southeast borderland of the Tibetan Plateau ［J］.J Geophys Res,110(B11409).doi: 10.1029/2004JB003421.
Shen Z K,Sun J,Zhang P,et al.2009.Slip maxima at fault junctions and rupturing of barriers during the 12 May 2008 Wenchuan earthquake ［J］.Nature Geosciences,2: 718-724.
Wang Q L,Cui D,Zhang X, et al., 2009,Coseismic vertical deformation of the M_S 8.0 Wenchuan earthquake from repeated levelings and its constraint on listric fault geometry ［J］.Earthquake Sciences,22: 595-602.
Xu Z,Ji S,Li H,et al.2008.Uplift of the Longmen Shan range and the Wenchuan earthquake ［J］.Episodes,31: 291-301.
Xu X,Wen X,Yu G, et al., 2009,Coseismic reverse- and oblique-slip surface faulting generated by the 2008 M_W 7.9 Wenchuan earthquake,China ［J］.Geology,37: 515-518.
Zhang P,Shen Z,Wang M,et al.2004.Continuous deformation of the Tibetan Plateau from global positioning system data ［J］.Geology,32: 809-812.
Zhang P Z,Wen X Z,Shen Z K,et al.2010. Oblique high-angle listric-reverse faulting and associated straining processes: The Wenchuan earthquake of 12 May 2008,Sichuan,China ［J］.Annu Rev Earth Planet Sci,38: 353-382.
Zhang Y,Feng W P,Xu LS,et al.2009. Temporal-spatial rupture process of M_S 8.0 Wenchuan earthquake of 2008 ［J］.Sci China (Ser D): Earth Sci,38.doi: 10.100 7/s11430-008-0148-7.
Zhao Z,Wang B,Long S, et al. 2001. The tectonic active characteristic of the earthquake sequence with magnitude 5.0 in Mianzhu Qingping,Sichuan in 1999 ［J］.Seism and Geomagn Observ and Res,22: 30-37.
Zhu S B,Zhang P Z.2010.Numeric modeling of the strain accumulation and release of the 2008 Wenchuan,Sichuan,China,earthquake ［J］.Bull Seism Soc Am,100: 2825-2839.
Zhu S B,Zhang P.2012.FEM simulation of interseismic and coseismic deformation associated with the 2008 Wenchuan Earthquake［J］. Tectonophysics.doi: 10.1016/j.tecto.2012.06.024.

[1]	YU Shu-yuan, HUANG Xian-liang, ZHENG Hai-gang, LI Ling-li, LUO Jia-ji, DING Juan, FAN Xiao-ran. THE COSEISMIC RUPTURE MODEL AND STRESS CHANGE OF THE 2022 MENYUAN M_W6.7 EARTHQUAKE [J]. SEISMOLOGY AND GEOLOGY, 2023, 45(1): 286-303.
[2]	SONG Dong-mei, WANG Hui, SHAN Xin-jian, WANG Bin, CUI Jian-yong. A NOVEL EXTRACTION METHOD OF PRE-EARTHQUAKE GRACE GRAVITY ANOMALY INFORMATION BASED ON MAXIMUM SHEAR STRAIN [J]. SEISMOLOGY AND GEOLOGY, 2022, 44(6): 1539-1556.
[3]	ZHANG Li-juan, WAN Yong-ge, WANG Fu-chang, JIN Zhi-tong, CUI Hua-wei. GEOMETRY OF SEISMOGENIC FAULTS OF THE 2021 YANGBI EARTHQUAKE SEQUENCE DETERMINED BY FUZZY CLUSTERING ALGORITHM [J]. SEISMOLOGY AND GEOLOGY, 2022, 44(6): 1634-1647.
[4]	CHEN Li-juan, CHEN Xue-zhong, LI Yan-e, GONG Li-wen. RELATIONSHIP BETWEEN DECREASING AMPLITUDE OF b-VALUE AND THE SEISMOGENIC ZONE OF THE WENCHUAN M_S8.0 EARTHQUAKE [J]. SEISMOLOGY AND GEOLOGY, 2022, 44(4): 1046-1058.
[5]	WANG Xiao-shan, WAN Yong-ge. CHARACTERISTICS OF THE CRUSTAL STRESS FIELD AND ITS DIRECTION CONVERGENCE BEFORE THE WENCHUAN EARTHQUAKE [J]. SEISMOLOGY AND GEOLOGY, 2022, 44(2): 363-377.
[6]	GUO Shu-song, ZHU Yi-qing, XU Yun-ma, LIU Fang, ZHAO Yun-feng, ZHANG Guo-qing, ZHU Hui. GRAVITY EVIDENCE OF META-INSTABLE STATE BEFORE THE 2008 WENCHUAN EARTHQUAKE [J]. SEISMOLOGY AND EGOLOGY, 2021, 43(6): 1368-1380.
[7]	LI Jia-ni, HAN Zhu-jun, LUO Jia-hong, GUO Peng. CHARACTERISTICS AND IMPLICATIONS OF SEISMIC ACTIVITY AROUND MINSHAN ACTIVE BLOCK IN EASTERN MARGIN OF QINGHAI-TIBET PLATEAU [J]. SEISMOLOGY AND EGOLOGY, 2021, 43(6): 1459-1484.
[8]	LI Chuan-you, ZHANG Jin-yu, WANG Wei, SUN Kai, SHAN Xin-jian. THE SEISMOGENIC FAULT OF THE 2021 YUNNAN YANGBI M_S6.4 EARTHQUAKE [J]. SEISMOLOGY AND GEOLOGY, 2021, 43(3): 706-721.
[9]	LI Zhi-min, LI Wen-qiao, LI Tao, XU Yue-ren, SU Peng, GUO Peng, SUN Hao-yue, HA Guang-hao, CHEN Gui-hua, YUAN Zhao-de, LI Zhong-wu, LI Xin, YANG Li-chen, MA Zhen, YAO Sheng-hai, XIONG Ren-wei, ZHANG Yan-bo, GAI Hai-long, YIN Xiang, XU Wei-yang, DONG Jin-yuan. SEISMOGENIC FAULT AND COSEISMIC SURFACE DEFORMATION OF THE MADUO M_S7.4 EARTHQUAKE IN QINGHAI, CHINA: A QUICK REPORT [J]. SEISMOLOGY AND GEOLOGY, 2021, 43(3): 722-737.
[10]	CUI Ren-sheng, ZHAO Cui-ping, ZHOU Lian-qing, CHEN Yang. SEISMICITY FEATURE AND SEISMOGENIC FAULT OF THE M_S6.4 EARTHQUAKE SEQUENCE ON JANUARY 19, 2020 IN JIASHI, XINJIANG [J]. SEISMOLOGY AND GEOLOGY, 2021, 43(2): 329-344.
[11]	LIU Xu-zhou, SHEN Xu-zhang, HE Xiao-hui, PU Ju. RELOCATION OF THE 28 OCTOBER 2019 XIAHE M5.7 EARTHQUAKE SEQUENCE AND ANALYSIS OF SEISMOGENIC FAULT [J]. SEISMOLOGY AND GEOLOGY, 2021, 43(1): 197-208.
[12]	LAN Jian, CHEN Xiao-li. EVOLUTION CHARACTERISTICS OF LANDSLIDES TRIGGERED BY 2008 M_S8.0 WENCHUAN EARTHQUAKE IN YINGXIU AREA [J]. SEISMOLOGY AND GEOLOGY, 2020, 42(1): 125-146.
[13]	XU Liang-xin, RAN Yong-kang, LIANG Ming-jian, WU Fu-yao, GAO Shuai-po, WANG Hu. GEOMETRIC DISTRIBUTION AND CHARACTERISTICS OF THE SURFACE RUPTURE OF TWO HISTORICAL EARTHQUAKES IN THE BARKOL BASIN, XINJIANG [J]. SEISMOLOGY AND GEOLOGY, 2020, 42(1): 1-17.
[14]	ZHU Chuan-hua, SHAN Xin-jian, ZHANG Guo-hong, JIAO Zhong-hu, ZHANG Ying-feng, LI Yan-chuan, QIAO Xin. TWO DIMENSIONAL MODEL ON RELATION BETWEEN THERMAL ANOMALY BEFORE WENCHUAN EARTHQUAKE AND TECTONIC STRESS [J]. SEISMOLOGY AND GEOLOGY, 2019, 41(6): 1497-1510.
[15]	SONG Dong-mei, XIANG Liang, SHAN Xin-jian, YIN Jing-yuan, WANG Bin, CUI Jian-yong. THE METHOD OF CONSTRUCTING IONOSPHERIC TEC BACKGROUND FIELD BASED ON SVR MODEL [J]. SEISMOLOGY AND GEOLOGY, 2019, 41(6): 1511-1528.

SEISMOGENIC STRUCTURE AND RUPTURE MECHANISM OF THE M_S 8.0 WENCHUAN EARTHQUAKE

汶川地震的发震构造与破裂机理

PDF (PC)

Knowledge

Abstract

Cite this article

share this article

References

Related Articles 15

Recommended Articles

Metrics

Comments