1988 Lancang–Gengma earthquakes

Major earthquakes in the Myanmar–China border region November 2024 1988 Lancang–Gengma earthquakes China–Myanmar border region22.789 N 99.611 E region:CN-53_type:event inline,title China#Yunnan 1988-11-06 13:03:19 1988-11-06 13:15:43 419867 usp0003nks 6 November 1988 21:03 21:15 18 km 15 km w 7.0 yes Lancang–Gengma Fault Zone Strike-slip China, Myanmar and Thailand CN¥ 2.05 billion IX, 10 600+ 748–939 dead, 7,700 injured 419869 usp0003nkt w 6.9 On 6 November 1988, two earthquakes struck Lancang and Gengma counties, Yunnan, near the China–Myanmar border. The first earthquake measured moment magnitude (w) 7.0, occurring at 21:03 CST. Twelve minutes later, a w 6.9 earthquake occurred about 60 km to north–northwest. They were caused by movement along the Lancang–Gengma Fault Zone, a 210 km long right-lateral strike-slip fault. Both earthquakes generated oblique-normal surface ruptures with larger displacements reported following the second event. These earthquakes were assigned a maximum China seismic intensity of IX and X, respectively. Between 748 and 939 people were killed; more than 7,700 were injured, and damage was estimated at CN¥ 2.05 billion. An additional 267,000 people were left homeless. Moderately large aftershocks continued to rock the region, causing additional casualties and damage. During initial recovery efforts, supplies had to be airlifted because landslides blocked roads to the affected areas. Several thousand soldiers participated in providing relief. The Chinese government made an appeal for international assistance. Tectonic setting 200px|thumb|left|A simplified diagram of bookshelf-style faulting Situated between the Sagaing and Red River faults, the Shan Plateau contains a network of left- and right-lateral strike-slip faults that accommodate crustal rotation and extrusion of the Sunda Block and deformation caused by the India–Asia continental collision.Yu Wang Kerry Sieh Soe Thura Tun Kuang-Yin Lai Than Myint 2014 Active tectonics and earthquake potential of the Myanmar region https://authors.library.caltech.edu/47518/1/jgrb50602.pdf Journal of Geophysical Research: Solid Earth 119 4 3767–3822 10.1002/2013JB010762 2014JGRB..119.3767W free This tectonically active zone extends across China, Myanmar, Laos, Thailand, and Vietnam, measuring 700 km long and 400 km wide.Shi X. Wang Y. Sieh K. Weldon R. Feng L. Chan C. H. Liu-Zeng J. Fault Slip and GPS Velocities Across the Shan Plateau Define a Curved Southwestward Crustal Motion Around the Eastern Himalayan Syntaxis Journal of Geophysical Research: Solid Earth 2018 123 3 2502–2518 10.1002/2017JB015206 2018JGRB..123.2502S free 10220/45249 free The regional tectonics are driven by the relative motion between two major right-lateral structures; the Sagaing Fault, a transform boundary between the Burma and Sunda plates, and the Red River Fault of southwest China. Movement between the two major structures divides the crust between them into clockwise-rotating blocks, forming a "bookshelf faulting" zone. Left-lateral faults run roughly perpendicular to the strike of the Sagaing and Red River faults, along the boundaries of these blocks. Meanwhile, right-lateral structures within these blocks occur along pre-existing fractures with strikes that are parallel to the two dominant faults.Lingyun Ji Qingliang Wang Jing Xu Cunwei Ji The July 11, 1995 Myanmar–China earthquake: A representative event in the bookshelf faulting system of southeastern Asia observed from JERS-1 SAR images 2017 https://www.sciencedirect.com/science/article/abs/pii/S0303243416301763 International Journal of Applied Earth Observation and Geoinformation 55 43–51 10.1016/j.jag.2016.10.006 2017IJAEO..55...43J 0303-2434 subscription The left-lateral fault systems are dominant; following an east–northeast or east–west trend for several hundred kilometers. The longest runs for about 370 km in the southern plateau. These faults exhibit obvious left-lateral displacements in rivers such as the Mekong and Salween and their tributaries. Some of these faults produce "hairpin" shape offsets suggesting the faults may have been left-lateral before reversing slip about 5 to 20 million years ago. The right-lateral structures are less dominant, and follow a north- to north-northwest or northwest strike. They can be divided into two systems; the western faults run subparallel to the Sagaing Fault while the northeast runs subparallel to the Red River Fault. The longest of these are the 400 km Wuliang Shan Fault Zone located southwest of the Red River and the 500 km Kyaukkyan Fault east of the Sagaing Fault. The earthquakes of 1988 were the result of slip along a dextral fault zone.Socquet Pubellier Anne Manuel 29 March 2004 Cenozoic deformation in western Yunnan (China–Myanmar border) http://www.geo.tu-freiberg.de/tektono/downloadfiles/Socquet&Pubellier%20eastern%20Myanmar%20JAES%2024,%202005.pdf Journal of Asian Earth Sciences 24 4 495–515 10.1016/j.jseaes.2004.03.006 https://web.archive.org/web/20170808093322/http://www.geo.tu-freiberg.de/tektono/downloadfiles/Socquet&Pubellier%20eastern%20Myanmar%20JAES%2024,%202005.pdf 8 August 2017 Consequently, many earthquakes in the region such as in 1912, 1913, 1923, 1925, 1935, 1941, 1950, 1970, 1971, 1976, 1983, 1988, 1995, 2007 and 2011 are caused by strike-slip faulting on one of these fault zones. 10.1016/j.jseaes.2020.104470 Stress evolution on active faults in the southwestern Yunnan region, southeastern Tibetan Plateau, and implications for seismic hazard 2020 Li Yujiang Shao Zhigang Shi Fuqiang Chen Lianwang Journal of Asian Earth Sciences 200 104470 2020JAESc.20004470L 224901911 Earthquakes Earthquake rupture The first earthquake measuring w 7.0 occurred at 21:03 CST on 6 November with an epicenter 21.7 km east–southeast of Zhutang in Lancang County, near the Myanmar–China border.ISC-GEM Global Instrumental Earthquake Catalogue (1900–2009) http://www.isc.ac.uk/iscgem/index.php ISC 27 June 2022 International Seismological Centre Version 9.1M 7.7 - 145 km NW of Jinghong, China 1988 usp0003nks Twelve minutes later, at 21:15 CST, a w 6.9 earthquake struck 63 km north–northwest of the first. The mainshock was caused by right-lateral strike-slip faulting at a shallow depth. These earthquakes originated along the Lancang Fault Zone (also known as the Lancang–Gengma Fault Zone), a 210 km long right-lateral strike-slip fault trending north–northwest. The northern segment comprise a single strand while southern section features a complex network of individual branches. A 1997 geologic map showed that the fault initially displaced a batholith 30 km left-laterally while right-lateral geomorphic features indicate its slip direction recently reversed. The total right-lateral displacement in the Nanguo River valley is estimated at 17 km. An average slip rate of about 3.4 mm per year was derived by assuming right-lateral slip initiated 5 million years ago; near the upper-bound rate derived from geodetic data (0–4 mm per year). The Lancang–Gengma Fault Zone comprise two north and south segments; the Gengma–Hanmuba and Lancang–Nanliu faults. The Muga–Heihe and Xiaoheijiang faults intersect these segments to form geometric seismic barriers. The first event initiated on the Lancang–Nanliu Fault where it intersects the northwest-trending Muga–Heihe Fault, rupturing bilaterally, 38 km northwest and 32 km southeast, for about 19 seconds at a velocity of 2 km per second. The second earthquake, likely triggered by the first, occurred 60 km northwest. A seismic rupture barrier between both segments may have stopped the northwest-propagating rupture of the first event, but was later breached, causing the second earthquake on the Gengma–Hanmuba Fault. This event initiated at the intersection with the east–west trending Xiaoheijiang Fault.Mozaffari Parviz Wu Zhong-Liang Chen Yun-Tai Rupture process of November 6, 1988, Lancang-Gengma, Yunnan, China, earthquake of M s=7.6 using empirical Green's function deconvolution method 1988 Acta Seismologica Sinica 11 1 1–12 1998AcSSn..11....1M 10.1007/BF02650450 129586363 https://www.proquest.com/openview/4aa806b568f04816549d94079c59b5c5/1?pq-origsite=gscholar&cbl=54963 subscription Surface rupture The first earthquake generated a surface-rupture zone about 35 km long and 2–3 km across. It comprised four generally continuous linear zones of extensional ground fractures and fault scarps. Each individual strand were several hundred metres to 6 km long. In the central rupture zone, along the western bank of the Heihe River, three northwest trending left-stepped fault scarps, each more than a hundred meters long, cut across the Carboniferous shale and Quaternary alluvium of a small ridge. A maximum vertical offset of 1.5 m and right-lateral offset of 1.4 m was associated with the first event. The southern segment cuts through limestone, measuring 300 m long, 3–5 m wide and forming a fissure 3 m deep.Wang Hui Qiang Zuji Yuan Zhuzhong Wang Yanglong Zhang Hua Zhao Xiang Gu Yishan 1992 Distribution of seismic intensities of the November 6, 1988, Lancang-Gengma earthquakes and their surface ruptures in Yunnan Province, China Acta Seismologica Sinica 5 2 343–354 1992AcSSn...5..343W 10.1007/BF02651701 129529222 The second earthquake was associated with a separate 24 km long rupture. A 5 km long rupture developed on the eastern flank of Mount Meilengshan, where it produced a maximum throw of 3.5 m and right-lateral slip of 3 m. Along the northern Xiaoheijiang River bank, on the southeastern ridge of Mount Meilengshan, the fault cuts through limestone, displacing the western block upwards and eastern block downwards. At the top of the ridge, a tree was severed and displaced 0.9 m laterally and 0.52 m vertically. Aftershocks By 20 December, over 600 aftershocks greater than s 3.0 were recorded by the Kunming Telemetered Seismic Network. Three of the largest had s of 6.1, 6.3 and 6.7 on 15, 27 and 30 November, respectively. The aftershock distribution aligned with the north–northwest trending fault responsible for the earthquakes. 10.1029/89EO00376 Lancang—Gengma Earthquake: A Preliminary Report on the November 6, 1988, Event and its Aftershocks 1989 Chen Yuntai Wu Francis T. Eos, Transactions American Geophysical Union 70 49 1527 1989EOSTr..70.1527C Some caused additional damage and injuries.M 5.5 – Myanmar-China border region 1988 usp0003p8b M 6.1 – Myanmar-China border region 1988 usp0003pcn A w 5.6 aftershock on 7 May 1989 killed 1 and injured 91 others. M 5.6 – Myanmar-China border region 1988 usp0003uz4 Intensity thumb|Strong ground motion map for the first mainshock|right|250px A combined isoseismal map for both earthquakes was published in Acta Seismologica Sinica in 1992. The isoseismal lines were generally elliptical-shaped with a northwest–southeast trend. For the first event, a maximum intensity of IX was assigned to a 36 km by 6 km area based on liquefaction along a river. Wood and bamboo walls collapsed, as did subterranean buildings in the area. The intensity VIII zone encompassed the intensity IX zone. There, many adobe and wooden-framed buildings were damaged. For the second event, a 12 km by 2–4 km area around the epicenter was assigned intensity X. Rockfalls occurred on the eastern slopes of Mount Meilengshan while two landslides occurred along the Xiaoheijiang Fault: one 1,000 m by 900 m and the other 900 m by 720 m. At six villages and towns within the intensity IX zone,Mangwong, Mengsheng, Yanglong, Tuanjie, Yanshai and Bangduo brick and reinforced concrete buildings collapsed. Intensity VII effects were reported in settlements further awayLangcang, Cangyuan, Shangyun, Dalaba, and Shuangjiang and in parts of Myanmar. In this zone, damage was limited to fallen tiles, dislodged plaster and small cracks in walls while adobe buildings were cracked. The ground motion in Chiang Mai, Chiang Rai and tall buildings of Bangkok were assigned V–VI (Moderate–Strong) on the Modified Mercalli intensity scale.State of seismic risk mitigation in Thailand Lukkunaprasit Panitan Chulalongkorn University 1989 Thailand en http://cidbimena.desastres.hn/docum/crid/Nov-Dic2003/pdf/eng/doc6973/doc6973-contenido%20.pdf 4 March 2022 https://web.archive.org/web/20220304010707/http://cidbimena.desastres.hn/docum/crid/Nov-Dic2003/pdf/eng/doc6973/doc6973-contenido%20.pdf Damage and casualties On 8 November, China's State Seismology Bureau placed the number of dead at 18 while Xinhua reported 37 deaths. The Peoples’ Central Broadcasting Station and Radio Beijing, citing a reporter, said about 600 people were killed or injured, with many from the village of Shanmato which was obliterated, though this initial report was not independently verified.Associated Press 8 November 1988 Chinese quake registers 7.6, death toll hits 600 The Observer http://www.archives.nd.edu/observer/v22/1988-11-08_v22_049.pdf live 22 January 2021 https://web.archive.org/web/20211123043005/http://archives.nd.edu/Observer/v22/1988-11-08_v22_049.pdf 23 November 2021 At the time of the earthquakes, the population of Lancang and Gengma counties were 237,000 and 81,000, respectively.China says toll from quake hits 938, will increase https://cdnc.ucr.edu/?a=d&d=SBS19881109.1.3&srpos=25&e=05-11-1988-----en--20--21-byDA-txt-txIN-+earthquake------- 15 May 2023 New York Times Desert Sun 9 November 1988 The civil affairs ministry's Disaster Relief Office said poor communication network made assessing the casualties difficult. On 9 November, officials placed the death toll at 938. However the state-run evening news said 600 people died and 578 were injured while its English-language counterpart put the toll at 900. Kristof Nicholas D. 9 November 1988 Toll Reported in China Earthquake Reaches 938 The New York Times https://www.nytimes.com/1988/11/09/world/toll-reported-in-china-earthquake-reaches-938.html https://web.archive.org/web/20180130105940/https://www.nytimes.com/1988/11/09/world/toll-reported-in-china-earthquake-reaches-938.html 30 January 2018 Later, Chinese officials lowered the number of dead to 730, rescinding the higher figure. They said the higher figure was not officially announced but United Nations agencies obtained it via the civil affairs ministry and it was widely reported.Kristof Nicholas D. Chinese Disclose That Quake In 1970 Killed About 10,000 https://www.nytimes.com/1988/11/19/world/chinese-disclose-that-quake-in-1970-killed-about-10000.html 23 July 2022 The New York Times 19 November 1988 https://web.archive.org/web/20180727120701/https://www.nytimes.com/1988/11/19/world/chinese-disclose-that-quake-in-1970-killed-about-10000.html 27 July 2018 The International Disasters Data Base listed 939 deaths.Ramirez Marizen Peek-Asa Corinne 2005 Epidemiology of Traumatic Injuries from Earthquakes https://academic.oup.com/epirev/article/27/1/47/520816 Epidemiologic Reviews 21 1 47–55 10.1093/epirev/mxi005 15958426 free subscription It was regarded as China's "worst earthquake in more than a decade".Chinese earthquake worst there in decade https://cdnc.ucr.edu/?a=d&d=DS19881109.2.20&srpos=18&e=07-11-1988-----en--20--1-byDA-txt-txIN-+earthquake------- 16 May 2023 Desert Sun 9 November 1988 A2 The Yunnan Provincial Earthquake Bureau said 748 people died; at least 7,700 people seriously injured; over 3 million affected and 267,000 homeless.Yang Jideng Wang Shiqin 1988年11月6日云南省澜沧-耿马7.6、7.2级地震 https://data.earthquake.cn/data/data/zhenli/zhwei/html/zhenli082.htm National Seismology Data Center Yunnan Seismological Bureau 22 February 2021 https://web.archive.org/web/20210711093432/https://data.earthquake.cn/data/data/zhenli/zhwei/html/zhenli082.htm 11 July 2021 The death toll could have been higher had these earthquakes struck near a city; additionally, many residents were outdoors at the time, which prevented more deaths. In Lancang County, at least 607 people died including 279 deaths in the town of Zhanmapo.Kristof Nicholas D. China now says earthquake left 100,000 homeless https://cdnc.ucr.edu/?a=d&d=SBS19881110.1.4&srpos=34&e=05-11-1988-----en--20--21-byDA-txt-txIN-+earthquake------- 15 May 2023 The New York Times 10 November 1988 Heavy damage and causalties were reported in 17 counties; many homes, roads and communication lines in Lancang and Mengliang counties were destroyed.UN Department of Humanitarian Affairs China – Earthquake Nov 1988 UNDRO Information Reports 1–7 https://reliefweb.int/report/china/china-earthquake-nov-1988-undro-information-reports-1-7 ReliefWeb 8 November 1988 An estimated 200,000 buildings including 144,000 houses were destroyed; another 934,000 buildings were damaged. About 1,000 schools, 98 clinics and 29 reservoirs were also destroyed. Many homes constructed of wood and mud, collapsed, killing their inhabitants. Rockslides with a total accumulated volume of 1,000,000 m3 damaged highways and blocked rivers, halting water transportation. The total cost of damage was estimated at CN¥ 2.05 billion. Some buildings did not suffer heavy damage because of improved designs or seismic retrofitting. Among them, a cinema and an apartment which were strengthened to survive intensity VIII–IX conditions were undamaged.Hu Qingchang Chung Yicun Yunnan November 6, 1988; M7.6, 7.2 Earthquakes https://www.eeri.org/1988/11/yunnan-2/#eeri 19 May 2021 Earthquake Engineering Research Institute 1989 https://web.archive.org/web/20130801042800/https://www.eeri.org/1988/11/yunnan-2/#eeri 1 August 2013 In Thailand, damage was reported in Chiang Rai. In Bangkok, people on high-rise buildings felt weak shaking. The highest floors of the 27-story Charn Issara Tower swayed for a few minutes. The earthquakes were also felt in Laos, Vietnam and Bangladesh.Quakes hit China and Thailand https://eresources.nlb.gov.sg/newspapers/digitised/page/newpaper19881107-1.1.11 27 June 2024 The New Paper 7 November 1988 11 Response thumb|Gengma County earthquake relief monument The Yunnan government ordered medical and relief supplies be airlifted to the affected areas as landslides blocked off roads. The governor of Yunnan Province, He Zhiqiang, along with several medical doctors travelled to the region. Military rescue and medical personnel reached the affected villages on 8 November.Teams reach quake area https://cdnc.ucr.edu/?a=d&d=SRPD19881109.1.15&srpos=31&e=05-11-1988-----en--20--21-byDA-txt-txIN-+earthquake------- 15 May 2023 Press Democrat 9 November 1988 8 132 19 The convoy comprised 30 military trucks which joined several thousand soldiers who were already in the region assisting those affected.Tyson James L. 9 November 1988 Peking sends help to Yunnan, 'China's earthquake center' The Christian Science Monitor https://www.csmonitor.com/1988/1109/oquak-f.html 22 January 2021 Chinese officials appealed for international assistance, with the World Food Programme and United Nations Development Programme saying that authorities were open to aid. These agencies also said that plastic sheets for shelter, medicine and food were needed.China wants aid as more tremors expected https://eresources.nlb.gov.sg/newspapers/digitised/page/straitstimes19881110-1.1.3 27 June 2024 Agence France-Presse The Straits Times 10 November 1988 3 At a press conference following the earthquakes, officials disclosed that the 1970 Tonghai earthquake killed 10,000 people. Knowledge about the 1970 earthquake was never immediately revealed as it occurred during the Cultural Revolution.Associated Press 10 July 2010 Hundreds injured in China earthquake The Guardian https://www.theguardian.com/world/2009/jul/10/china-earthquake 22 January 2021 In the early decades of China's political history, natural disasters and accidents would not be publicly disclosed unless foreign nationals were involved, but started being publicized several years ago. See also List of earthquakes in 1988 List of earthquakes in China List of earthquakes in Myanmar List of earthquakes in Yunnan List of earthquakes in Thailand Notes References External links 419867 419869 Category:Earthquakes in Myanmar Category:Earthquakes in Thailand Category:Earthquakes in Yunnan Category:1988 disasters in China Category:November 1988 in Asia Category:1988 earthquakes Category:Lancang Lahu Autonomous County Category:Doublet earthquakes Category:1988 in Burma Category:China–Myanmar border Category:1988 disasters in Myanmar Category:November 1988 in China