GEOMETRIC DISTRIBUTION AND CHARACTERISTICS OF THE SURFACE RUPTURE OF TWO HISTORICAL EARTHQUAKES IN THE BARKOL BASIN, XINJIANG

doi:10.3969/j.issn.0253-4967.2020.01.001

Abstract

Abstract:

Surface rupture zone of historical earthquake is the most intuitive geomorphological response to fault activity. The rupture pattern, coseismic displacement and its geometric spatial distribution are important for determining segmentation and long-term movement behaviors of active fault. In the Barkol Basin of Xinjiang, according to the comprehensive result from remote sensing image interpretation, field surgery, high-resolution small unmanned aerial vehicles photography, terrain deformation measurements and trench excavation on geomorphological points, not only the new surface ruptures of the two M71/2 historical earthquakes in Barkol in 1842 and 1914 were found and defined between Xiongkuer and the southwest of Barkol County in southwestern part of the basin, but also the latest deformation evidence of the EW fold-up faults in the eastern part of the Basin was identified.
Combined with the ancient document analysis of the two historical earthquakes, we finally conclude that the surface rupture zone in the western segment on the southern margin of the Barkol Basin is the seismogenic structure of the M71/2 earthquake in 1842. The surface rupture zone is mainly characterized by left-lateral strike-slip, roughly with en echelon arrangement spreading from Xiongkuer to the south of Barkol County. The length of the surface rupture zone determined by field investigation is at least about 65km, and the maximum horizontal displacement appears around the Xiongkuer Village. At the same time, the surface rupture zone gradually shows more significant thrust extrusion from west to east, and has a tendency of extension towards the central of the Barkol Basin. The average observed displacement of the entire surface rupture obtained by counting the coseismic offsets of multiple faulted gullies is(4.1±1.0)m, with the coseismic characteristic displacement of ~4m. The epicenter position should appear at the place with the largest horizontal dislocation amount near Xiongkuer Village.
In addition, the length of the fold-blind fault zone in the vicinity of the Kuisu Town and the eastward extension to the Yanchi Township of the Yiwu Basin, which was discovered in the center of the Barkol Basin, is about 90km. The folded blind fault causes significant fold deformation in the latest sedimentary strata such as floodplain, and in addition, as shown on many outcrop sections, the bending-moment faults associated with the coseismic fold deformation have ruptured the surface. Therefore, the location of the epicenter should be located at the maximum fold deformation, which is near the Kuisu Town. The new research results not only further improve the understanding of the epicenter location and seismogenic faults of the two historical earthquakes in the Barkol Basin, but also provide an important reference for analyzing regional seismic hazards.

Key words: eastern Tianshan, Barkol, historical earthquakes, seismogenic fault, co-seismic surface rupture

摘要：

地震地表破裂带是断裂活动最为直观的地貌证据, 其破裂样式、同震位移量及空间几何展布特征是判定活动断裂分段及长期活动习性的重要依据。文中在对新疆巴里坤盆地开展活动断裂调查研究的过程中, 综合遥感解译、野外断裂踏勘、小型无人机航拍、地表断错位移分析以及古地震槽探等方法, 根据在巴里坤盆地南缘断裂西段的雄库尔—邵家庄之间和巴里坤盆地中央东部等多处新发现的总体呈EW向展布的最新地表构造形变遗迹, 并对比历史文献记载中这2次地震震害的分布特征, 进一步厘定了巴里坤1842年和1914年2次M71/2历史地震地表破裂的空间展布及特征。结果表明, 沿巴里坤盆地南缘断裂西段分布的1842年M71/2地震地表破裂带的同震运动以左旋走滑为主, 在雄库尔与巴里坤县城之间呈雁列状展布, 且自西向东还具有向巴里坤盆地中央扩展的趋势。新厘定的地表破裂带长度至少可达65km, 最大水平位错量出现在雄库尔—洛包泉一带, 多个冲沟水系的同震位错平均观测值为(4.1±1.0)m, 并具有约4m的特征位移量, 由此推断1842年M71/2历史地震的震中位置应在雄库尔—洛包泉一带。此外, 位于巴里坤盆地中央东部的奎苏镇—伊吾盆地盐池乡附近的褶皱盲断层带应是1914年M71/2地震的发震构造, 该地震的地表变形带全长约90km, 表现为河漫滩等最新地貌面和冲积砾石层的显著褶皱变形, 并且有多处露头剖面显示与同震褶皱变形伴生的弯矩断层已断错至地表。因此, 1914年M71/2地震的震中位置应在地表构造形变最为显著的奎苏镇东附近。文中取得的研究结果不仅进一步更新和完善了对巴里坤盆地2次历史地震震中位置及发震断裂的认识, 并可为分析区域地震危险性提供重要的参考资料。

关键词: 东天山, 巴里坤, 历史地震, 地表破裂带, 发震构造

CLC Number:

P315.2

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.

徐良鑫, 冉勇康, 梁明剑, 吴富峣, 高帅坡, 王虎. 新疆巴里坤1842年和1914年2次M71/2历史地震地表破裂的几何展布及特征[J]. 地震地质, 2020, 42(1): 1-17.

Figures/Tables 12

Fig. 1 Simplified map of the Late Pleistocene active faults around the Barkol Basin.

Fig. 2 Distribution map of Late Pleistocene active faults in the Barkol Basin.

Fig. 3 Typical landscape of surface rupture zone at Erchangquan.

Fig. 4 Typical landscape and the distribution of coseismic displacement along the surface rupture zone at Wujiazhuangzi.

Fig. 5 Distribution map of the surface rupture and the coseismic displacement at Saerqiaoke.

Fig. 6 Distribution map of the surface rupture and the trench profile sketch at the south of Jianshan.

Fig. 7 Distribution map of the surface rupture and the coseismic displacement at the west of Shaojiazhuang.

Fig. 8 Distribution map of the rupture trace and the trench profile sketch at Wubulake.

Fig. 9 Distribution map and the profile sketch of the Kuisu activity fold.

Fig. 10 The fold-deformed geomorphology GPS profile and the photo of deformed stratum profile on T1 terrace of Dasha River.

Fig. 11 Simplified map of the surface rupture in eastern Barkol Basin.

Fig. 12 Distribution map of the surface rupture with isoseisms maps of two historic earthquakes in Barkol Basin(after GU Gong-xu et al., 1983).

References 28

[1]	柏美祥, 麻勇, 今泉俊文, 等. 1999. 新疆鄯善碱泉子-巴里坤洛包泉活动断裂带研究[J]. 内陆地震, 13(4): 291—298.
	BAI Mei-xiang, MA Yong, Toshifumi I, et al.1999. Study on Jianquanzi-Luobaoquan active fault zone in Xinjiang[J]. Inland Earthquake, 13(4): 291—298(in Chinese).
[2]	陈祥玉. 1994. 关于新疆有争议的几次历史大震的研究[C]. 中国地震学会第5次学术大会论文摘要集.
	CHEN Xiang-yu.1994. Study of several controversial historical earthquakes in Xinjiang[C]. Abstracts of the Academic Conference of the Fifth Chinese Seismological Society(in Chinese).
[3]	冯先岳. 1995. 天山全新世活动断裂及古地震研究[J]. 内陆地震, 9(3): 217—226.
	FENG Xian-yue.1995. Holocene active faults and paleoearthquakes in Xinjiang[J]. Inland Earthquake, 9(3): 217—226(in Chinese).
[4]	冯先岳. 1997. 新疆古地震 [M]. 乌鲁木齐: 新疆科技卫生出版社.
	FENG Xian-yue.1997. Paleoseismology in Xinjiang [M]. Xinjiang Science and Health Press, Urumqi(in Chinese).
[5]	顾功叙, 林庭煌, 时振梁, 等. 1983. 中国地震目录: 公元前1831—公元1969年 [M]. 北京: 科学出版社: 266.
	GU Gong-xu, LIN Ting-huang, SHI Zhen-liang, et al.1983. China Earthquake Catalogue(1831BC—1969AD)[M]. Science Press, Beijing: 266(in Chinese).
[6]	江娃利. 1993. 航片判读新疆东天山巴里坤活动断裂带展布及变位地形特征[J]. 内陆地震, 7(4): 350—355.
	JIANG Wa-li.1993. The distribution and active characteristics of the Barkol active fault zone in the East Tien Shan of Xinjiang from aerophoto interpretation[J]. Inland Earthquake, 7(4): 350—355(in Chinese).
[7]	荆凤, 申旭辉, 冯春, 等. 2009. 中巴地球资源卫星数据在地震活断层研究中的应用: 以巴里坤断裂带为例[J]. 地震, 29(2): 48—56. doi: 10.3969/j.issn.1000-3274.2009.02.006.
	JING Feng, SHEN Xu-hui, FENG Chun, et al.2009. Application of CBERS -002 CCD data in earthquake active fault research: A case study of Barkol fault zone in Xinjiang[J]. Earthquake, 29(2): 48—56(in Chinese).
[8]	冉洪流. 2011. 中国西部走滑型活动断裂的地震破裂参数与震级的经验关系[J]. 地震地质, 33(3): 577—585. doi: 10.3969/j.issn.0253-4967.2011.03.008.
	RAN Hong-liu.2011. Empirical relations between earthquake magnitude and parameters of strike-slip seismogenic active faults associated with historical earthquakes in western China[J]. Seismology and Geology, 33(3): 577—585(in Chinese).
[9]	沈军, 李莹甄, 汪一鹏, 等. 2003. 阿尔泰山活动断裂[J]. 地学前缘, 10(S1): 132—141. doi: 10.3321/j.issn: 1005-2321.2003.z1.020.
	SHEN Jun, LI Ying-zhen, WANG Yi-peng, et al.2003. The active faults in Altai Mountains[J]. Earth Science Frontiers, 10(S1): 132—141(in Chinese).
[10]	王国灿, 赵璇, 陈超, 等. 2016. 西北断陷盆地覆盖区填图方法探索: 新疆巴里坤盆地填图实践[J]. 地质力学学报, 22(4): 809—821. doi: 10.3969/j.issn.1006-6616.2016.04.002.
	WANG Guo-can, ZHAO Xuan, CHEN Chao, et al.2016. Exploration of geological mapping methods on covered area of faulted basin in the Northwest China: A mapping practice in the Barkol Basin, Xinjiang[J]. Journal of Geomechanics, 22(4): 809—821(in Chinese).
[11]	吴富峣, 冉勇康, 陈立春, 等. 2016. 东天山3条地震地表破裂带的展布及其与2次历史地震的关系[J]. 地震地质, 38(1): 77—90. doi: 10.3969/j.issn.0253-4967.2016.01.006.
	WU Fu-yao, RAN Yong-kang, CHEN Li-chun, et al.2016. Distribution of 3 earthquake rupture zones in Esatern Tienshan and its relationship with 2 historical earthquakes[J]. Seismology and Geology, 38(1): 77—90(in Chinese).
[12]	吴中海, 周春景, 冯卉, 等. 2014. 青海玉树地区活动断裂与地震[J]. 地质通报, 33(4): 419—469. doi: 10.3969/j.issn.1671-2552.2014.04.003.
	WU Zhong-hai, ZHOU Chun-jing, FENG Hui, et al.2014. Active faults and earthquake around Yushu in eastern Tibetan plateau[J]. Geological Bulletin of China, 33(4): 419—469(in Chinese).
[13]	新疆维吾尔自治区地震局. 1985. 新疆维吾尔自治区地震资料汇编 [M]. 北京: 地震出版社.
	Seismological Bureau of Xinjiang Uygur Autonomous Region. 1985. Compilation of Earthquake Materials of Xinjiang Uygur Autonomous Region [M]. Seismological Press, Beijing(in Chinese).
[14]	杨章, 丁德轩. 1987. 1842年6月11日新疆巴里坤7.5级地震[J]. 西北地震学报, 9(2): 70—74.
	YANG Zhang, DING De-xuan.1987. The Barkol earthquake (M=7.5) on June 11, 1842 in Xinjiang[J]. Northwestern Seismological Journal, 9(2): 70—74(in Chinese).
[15]	Cunningham D.2013. Mountain building processes in intracontinental oblique deformation belts: Lessons from the Gobi Corridor, Central Asia[J]. Journal of Structural Geology, 46:255—282. doi: 10.1016/j.jsg.2012.08.010.
[16]	Cunningham D, Dijkstra A, Howard J, et al.2003a. Active intraplate strike-slip faulting and transpressional uplift in the Mongolian Altai[J]. Geological Society, London, Special Publications, 210(1): 65—87. doi: 10.1144/GSL.SP.2003.210.01.05.
[17]	Cunningham D, Owen L A, Snee L, et al.2003b. Structural framework of a major intracontinental orogenic termination zone: The easternmost Tien Shan, China[J]. Journal of the Geological Society, 160(3): 575—590. doi: 10.1144/0016-764902-122.
[18]	Cunningham D, Windley B F, Dorjnamjaa D, et al.1996. Late Cenozoic transpression in southwestern Mongolia and the Gobi Altai-Tien Shan connection[J]. Earth and Planetary Science Letters, 140(1-4): 67—81.
[19]	Lu S A, Li S, Zhai C H, et al.2013. Effects of hanging wall and footwall on demand of structural input energy during the 2008 Wenchuan earthquake[J]. Earthquake Engineering and Engineering Vibration, 12(1): 1—12. doi: 10.1007/s11803-012-0146—9.
[20]	Molnar P, Ghose S.2000. Seismic moments of major earthquakes and the rate of shortening across the Tien Shan[J]. Geophysical Research Letters, 27(16): 2377—2380. doi: 10.1029/2000gl011637.
[21]	Molnar P, Tapponnier P.1975. Cenozoic tectonics of Asia: Effects of a continental collision[J]. Science, 189(4201): 419—426.
[22]	Oglesby D D, Archuleta R J, Nielsen S B.1998. Earthquakes on dipping faults: The effects of broken symmetry[J]. Science, 280(5366): 1055—1059.
[23]	Somerville P, Smith N, Graves R W, et al.1997. Modification of empirical strong ground motion attenuation relations to include the amplitude and duration effects of rupture directivity[J]. Seismological Research Letters, 68(1): 199—222.
[24]	Sun K, Chen C, Du J, et al.2018. Determination of Cenozoic sedimentary structures using integrated geophysical surveys: A case study in the Barkol Basin, Xinjiang, China[J]. Journal of Applied Geophysics, 148:152—162. doi: 10.1016/j.jappgeo.2017.10.015.
[25]	Tapponnier P, Molnar P.1979. Active faulting and Cenozoic tectonics of the Tien Shan, Mongolia, and Baykal regions[J]. Journal of Geophysical Research, 84:3425—3459.
[26]	Wells D L, Coppersmith K J.1994. New empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement[J]. Bulletin of Seismological Society of America, 84(4): 974—1002.
[27]	Wu F Y, Ran Y K, Xu L X, et al.2017. Paleoseismological study of the late Quaternary slip-rate along the south Barkol Basin fault and its tectonic implications, eastern Tian Shan, Xinjiang[J]. Acta Geologica Sinica(English Edition), 91(2): 429—442. doi: 10.1111/1755-6724.13109.
[28]	Yu Y X, Gao M T.2001. Effects of the hanging wall and footwall on peak acceleration during the Jiji(Chi-Chi), Taiwan Province, earthquake[J]. Acta Seismologica Sinica, 14(6): 654—659. doi: 10.1007/bf02718076.