NEW CHRONOLOGICAL CONSTRAINT ON THE CO-SEISMIC SURFACE RUPTURE SEGMENTS ASSOCIATED WITH THE LITANG FAULT

doi:10.3969/j.issn.0253-4967.2015.02.009

Abstract

Abstract:

Detailed mapping shows that there are two segments of co-seismic surface ruptures on the Litang-Dewu left-lateral strike-slip fault. The north segment is about 25km long, with a strike about 135°NE. The maximum horizontal left-lateral displacement on the north one is~1.8m and located at the high floodplains on the north side of the Wuliang River near Cun'ge village, offsetting the linear ridges that were left behind by human activity. The south segment is about 41km, striking generally about 146°NE. The maximum horizontal left-lateral displacement is located at the piedmont near the north side of the Rongjia mountain pass and the river floodplain scarp here is offset about 3.2m. There is a surface rupture gap about 11km between these two co-seismic surface rupture segments. The distribution of the co-seismic surface ruptures acquired by detailed mapping in the field survey, the earthquake event revealed by the trench, the AMS-¹⁴C dating result, the historical records of earthquakes at least since AD 1729 in the study area and the visiting on the local people, show consistently that the northern co-seismic surface rupture segment is most possibly produced by the 1729 Litang earthquake. The 1948 Litang earthquake was only responsible for the southern surface rupture segment. However, if only according to the 2 sigma calendar calibrated results of ¹⁴C dating, it cannot be excluded the possibility that the north segment maybe was produced by some older large earthquake occurring at some time during the AD 1420 to AD 1690. The moment magnitude(M_W)of the 1729 earthquake is about 6.7 and that of the 1948 earthquake is about 7.0 calculated from the empirical relations between the earthquake magnitude and the rupture length.

Key words: co-seismic surface rupture, historical earthquake, seismic hazard assessment, Litang Fault, the 1948 Litang earthquake

摘要：

在开展理塘左旋走滑活动断裂带的同震地表破裂实测填图基础上, 结合历史地震资料及地震事件测年, 对该断裂带的最新同震地表破裂形成年代和震级进行了重新厘定。结果表明: 理塘活动断裂带的最新同震地表破裂可分为南、北2段, 其中北段最长约25km, 最大左旋错动量1.8m; 南段最长约41km, 最大左旋错动量3.2m。综合探槽揭露的地震事件及AMS-¹⁴C测年结果和历史地震资料的分析结果, 北段和南段同震地表破裂应为2次地震沿理塘断裂带不同段先、后破裂的结果, 属典型的分段破裂现象。其中北段破裂极可能是历史记载的1729年地震活动的产物, 而南段由1948年大地震所产生。根据震级和地表破裂长度的经验关系计算结果, 前者的矩震级(M_W)约为6.7, 后者约为7.0。2次大地震沿同一断裂分段破裂的现象表明, 该断层带尚未破裂的段可能是未来强震活动的危险地段。

关键词: 同震地表破裂, 历史地震, 地震危险性评价, 理塘断裂带, 1948年理塘地震

CLC Number:

P315.3⁺2

ZHOU Chun-jing, WU Zhong-hai, ZHANG Ke-qi, LI Jia-cun, JIANG Yao, TIAN Ting-ting, LIU Yan-hui, HUANG Xiao-jin. NEW CHRONOLOGICAL CONSTRAINT ON THE CO-SEISMIC SURFACE RUPTURE SEGMENTS ASSOCIATED WITH THE LITANG FAULT[J]. SEISMOLOGY AND GEOLOGY, 2015, 37(2): 455-467.

周春景, 吴中海, 张克旗, 李家存, 蒋瑶, 田婷婷, 刘艳辉, 黄小巾. 川西理塘活动断裂最新同震地表破裂形成时代与震级的重新厘定[J]. 地震地质, 2015, 37(2): 455-467.

References

国家地震局全国地震烈度区划编图组. 1979. 中国地震等烈度线图集【Z】. 北京: 地震出版社. 41.
Compiling Team of National Earthquake Intensity Zoning Map of China of State Seismological Bureau. 1979. Atlas of Isoseismal Maps of Chinese Earthquakes 【Z】. Seismological Press, Beijing. 41(in Chinese).
黄彩权. 1988. 四川理塘地震断裂与发震构造【A】. 见: 新疆维吾尔自治区地震局编.中国地震断层研究. 乌鲁木齐: 新疆人民出版社. 172—176.
HUANG Cai-quan. 1988. The Litang Fault(Sichuan Province)and the seismogenic structure 【A】. In: Earthquake Administration of Xinjiang Uygur Autonomous Region(ed). Earthquake Faults Study in China. Xinjiang People's Publishing House, Urumqi. 172—176(in Chinese).
马丹, 吴中海, 李家存, 等. 2014. 川西理塘断裂带的空间展布与第四纪左旋走滑活动的遥感影像标志【J】. 地质学报, 88(8): 1417—1435.
MA Dan, WU Zhong-hai, LI Jia-cun, et al. 2014. Geometric distribution and the Quaternary activity of Litang active fault zone based on remote sensing 【J】. Acta Geologica Sinica, 88(8): 1417—1435(in Chinese).
四川地震资料汇编编辑组. 1980. 四川地震资料汇编(一)【M】. 成都: 四川人民出版社.
Editorial Team of the Compilation of Earthquakes in Sichuan Province. 1980. Compilation of Earthquakes in Sichuan Province(1)【M】. Sichuan People's Publishing House, Chengdu(in Chinese).
四川省地震局地震地质队. 1988. 1948年理塘7.3级地震【J】. 四川地震, 4: 26—56.
Seismogeological Team of Sichuan Seismological Bureau. 1988. The 1948 Litang M7.3 Earthquake 【J】. Earthquake Research in Sichuan, 4: 26—56(in Chinese).
唐荣昌, 韩渭宾. 1993. 四川活动断裂与地震【M】. 北京: 地震出版社.
TANG Rong-chang, HAN Wei-bin. 1993. Active Faults and Earthquakes in Sichuan Province 【M】. Seismological Press, Beijing(in Chinese).
徐杰. 1979. 四川理塘强震区的地震地质特征【A】. 见: 国家地震局西南烈度队编. 川滇强震区地震地质调查汇编. 北京: 地震出版社. 85—91.
XU Jie. 1979. The seismogeological characteristics of the Litang meizoseismal area, Sichuan 【A】. In: Southwest Earthquake Intensity Survey Team, State Seismological Bureau(ed). Compilation of Seismic and Geological Survey Results on the Meizoseismal Areas in Sichuan-Yunnan. Seismological Press, Beijing, 85—91(in Chinese).
徐锡伟, 闻学泽, 于贵华, 等. 2005. 川西理塘断裂带平均滑动速率、地震破裂分段与复发特征【J】. 中国科学(D 辑), 35(6): 540—551.
XU Xi-wei, WEN Xue-ze, YU Gui-hua, et al. 2005. Average slip rate, earthquake rupturing segmentation and recurrence behavior on the Litang Fault zone, western Sichuan Province, China 【J】. Science in China(Ser D), 48(8): 1183—1196.
中央地震工作小组办公室. 1971. 中国地震目录(第一、第二合订)【M】. 北京: 科学出版社. 320—321.
Office of Central Earthquake Working Group. 1971. China Earthquake Catalogue(1-2)【M】. Science Press, Beijing. 320—321(in Chinese).
周春景, 吴中海, 尼玛次仁, 等. 2014. 青海玉树M_S7.1 级地震同震地表破裂构造【J】. 地质通报, 33(4): 551—566.
ZHOU Chun-jing, WU Zhong-hai, Nimaciren, et al. 2014. Structural analysis of the co-seismic surface ruptures associated with the Yushu M_S7.1 earthquake, Qinghai Province 【J】. Geological Bulletin of China, 33(4): 551—566(in Chinese).
周荣军, 陈国星, 李勇, 等. 2005. 四川西部理塘-巴塘地区的活动断裂与1989年巴塘 6.7 级震群发震构造研究【J】. 地震地质, 27(1): 31—43.
ZHOU Rong-jun, CHEN Guo-xing, LI Yong, et al. 2005. Research on active faults in Litang-Batang region, western Sichuan Province and the seismogenic structures of the 1989 Batang M6.7 earthquake swarm 【J】. Seismology and Geology, 27(1): 31—43(in Chinese).
周荣军, 闻学泽, 蔡长星, 等. 1997. 甘孜-玉树断裂带的近代地震与未来地震趋势估计【J】. 地震地质, 19(2): 115—124.
ZHOU Rong-jun, WEN Xue-ze, CAI Chang-xing, et al. 1997. Recent earthquakes and assessment of seismic tendency on the Garzê-Yushu Fault zone 【J】. Seismological Geology, 19(2): 115—124(in Chinese).
周荣军, 叶友清, 李勇, 等. 2007. 理塘断裂带沙湾段的晚第四纪活动性【J】. 第四纪研究, 27(1): 45—53.
ZHOU Rong-jun, YE You-qing, LI Yong, et al. 2007. Late Quaternary activity of the Shawan segment of the Litang Faults 【J】. Quaternary Sciences, 27(1): 45—53(in Chinese).
Erchie W, Burchfiel B C. 2000. Late Cenozoic to Holocene deformation in southwestern Sichuan and adjacent Yunnan, China, and its role in formation of the southeastern part of the Tibetan plateau 【J】. Geological Society of America Bulletin, 112(3): 413—423.
Wells D J, Coppersmiths K J. 1994. New empirical relations among magnitude, rupture length, rupture width, rupture area and surface displacement 【J】. Seismological Society of America Bulletin, 84(4): 974—1002.
WEN Xue-ze, MA Sheng-li, XU Xi-wei, et al. 2008. Historical pattern and behavior of earthquake ruptures along the eastern boundary of the Sichuan-Yunnan faulted-block, southwestern China 【J】. Physics of the Earth and Planetary Interiors, 168: 16—36.

[1]	ZHANG Yan, JI Zhi-wei, ZHAI Hong-yu, WU Chun-hao. GROUND MOTION SIMULATION CONSIDERING VELOCITY DISPERSION AND ITS IMPLICATIONS FOR SEISMIC HAZARD ASSESSMENT [J]. SEISMOLOGY AND GEOLOGY, 2024, 46(6): 1408-1425.
[2]	YOU Zi-cheng, BI Hai-yun, ZHENG Wen-jun, PENG Hui, LIANG Shu-min, DUAN Lei, QIN Yi-gen. FINE CHARACTERISTICS OF EARTHQUAKE SURFACE RUPTURE ZONE BASED ON HIGH-RESOLUTION REMOTE SENSING IMAGE: A CASE STUDY OF LITANG FAULT [J]. SEISMOLOGY AND GEOLOGY, 2023, 45(5): 1057-1073.
[3]	SHEN Hua-liang, YANG Yao, ZHOU Zhi-hua, RUI Xue-lian, LIAO Xiao-feng, ZHAO De-yang, LIANG Ming-jian, CHEN Meng-die, GUAN Zhi-jun, REN Hong-wei. GENESIS AND DEEP GEOTHERMAL PROCESS OF MAOYA HOT SPRINGS IN LITANG, WESTERN SICHUAN [J]. SEISMOLOGY AND GEOLOGY, 2023, 45(3): 689-709.
[4]	WANG Liao, XIE Hong, YUAN Dao-yang, LI Zhi-min, XUE Shan-yu, SU Rui-huan, WEN Ya-meng, SU Qi. THE SURFACE RUPTURE CHARACTERISTICS BASED ON THE GF-7 IMAGES INTERPRETATION AND THE FIELD INVESTIGA-TION OF THE 2022 MENYUAN M_S6.9 EARTHQUAKE [J]. SEISMOLOGY AND GEOLOGY, 2023, 45(2): 401-421.
[5]	WU Zhong-hai, Baima Duoji, YE Qiang, HAN Shuai, SHI Ya-ran, Nima Ciren, GAO Yang. THE QUATERNARY NORMAL FAULTING AND RECENT CO-SEISMIC SURFACE RUPTURE AND RELATED SEISMOLOGICAL SIGNIFICANCE ALONG THE ARU CO GRABEN SYSTEM IN NORTHERN NGARI, TIBET [J]. SEISMOLOGY AND GEOLOGY, 2023, 45(1): 67-91.
[6]	YAO Sheng-hai, GAI Hai-long, YIN Xiang, LIU Wei, ZHANG Jia-qing, YUAN Jian-xin. A DISCUSSION ON THE RELATIONSHIP BETWEEN THE SUR-FACE RUPTURE ZONE IN FRONT OF THE AMUNIKESHAN MOUNTAIN AND THE 1962 M6.8 EARTHQUAKE [J]. SEISMOLOGY AND GEOLOGY, 2022, 44(4): 976-991.
[7]	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.
[8]	XU Liang-xin, BIAN Ju-mei, HU Nan, TIAN Qin-hu, TIAN Wei-xin, DUAN Rui. THE ACTIVITY OF WESTERN LISHAN FAULT SINCE THE LATE PLEISTOCENE [J]. SEISMOLOGY AND GEOLOGY, 2019, 41(3): 561-575.
[9]	MA Ji, FENG Xi-jie, LI Gao-yang, LI Xiao-ni, SHI Ya-qin. TEXTUAL RESEARCH OF 1568 M7 GAOLING EARTHQUAKE IN SHAANXI AND ANALYSIS OF ITS SEISMOGENIC STRUCTURE [J]. SEISMOLOGY AND GEOLOGY, 2019, 41(1): 178-188.
[10]	YANG Hai-bo, YANG Xiao-ping, HUANG Xiong-nan, HU Zong-kai. LATE QUATERNARY TECTONIC DEFORMATION AROUND THE HUJIATAI ANTICLINE ALONG THE EAST SEGMENT OF THE FODONGMIAO-HONGYAZI FAULT, NORTHERN QILIAN SHAN: AN INSIGHT ON THE SEISMOGENIC PATTERN OF 1609 HONGYAZI M7 1/4 EARTHQUAKE [J]. SEISMOLOGY AND GEOLOGY, 2018, 40(5): 980-998.
[11]	YAN Xiao-bing, ZHOU Yong-sheng, LI Zi-hong, GUO Jin. A STUDY ON THE SEISMOGENIC STRUCTURE OF LINFEN M7(3/4) EARTHQUAKE IN 1695 [J]. SEISMOLOGY AND GEOLOGY, 2018, 40(4): 883-902.
[12]	YAO Qi, XING Hui-lin, XU Xi-wei, ZHANG Wei, LIU Jie. SIMULATION OF SEISMIC RISK IN THE DALIANGSHAN SUB-BLOCK AND ADJACENT AREAS USING THE NONLINEAR FRICTION FEM METHOD [J]. SEISMOLOGY AND GEOLOGY, 2018, 40(1): 171-185.
[13]	HAO Hai-jian, HE Hong-lin, WEI Zhan-yu, SHI Feng. GEOMETRIC CHARACTERISTICS OF CO-SEISMIC SURFACE RUPTURES AND ACTIVE FAULTS [J]. SEISMOLOGY AND GEOLOGY, 2017, 39(6): 1267-1282.
[14]	YUAN Dao-yang, LEI Zhong-sheng, WU Zhao, FENG Jian-gang. TEXTUAL RESEARCH OF LONGXI EARTHQUAKE IN 47 BC IN GANSU PROVINCE AND ANALYSIS OF ITS CAUSATIVE STRUCTURE [J]. SEISMOLOGY AND GEOLOGY, 2017, 39(4): 819-836.
[15]	LIANG Ming-jian, CHEN Li-chun, RAN Yong-kang, WANG Hu, LI Dong-yu. THE DISCUSSION FOR THE NEW ACTIVITY OF THE TIANQUAN SEGMENT OF LONGMENSHAN FAULT ZONE AND ITS RELATIONSHIP TO THE 1327 TIANQUAN EARTHQUAKE, SICHUAN [J]. SEISMOLOGY AND GEOLOGY, 2016, 38(3): 546-559.