1970 Tonghai earthquake

1970 earthquake in southwest China and northern Vietnam October 2024 1970 Tonghai earthquake 1970-01-04 17:00:41 799712 iscgem799712 yes 1970 01 05 01:00:41 Yunnan 7.1 w y 11 km on 24.19 N 102.54 E inline, title Strike-slip 10 Between USD 5 to 25 million People's Republic of China 10,000–15,621 dead 26,783 injured thumb|Tonghai Earthquake Memorial Monument, erected at Fengyi Pavilion of Xiushan Park An earthquake occurred in Tonghai, Yunnan province, China at 01:00:41 local time on 5 January 17:00:41 UTC on 4 January 1970 with a moment magnitude of 7.1 and a maximum Mercalli intensity of X (Extreme). The strike-slip rupture originated on the Red River Fault, which had not experienced an earthquake above magnitude 7 since 1700. At least 10,000 people were killed, making it one of the deadliest in its decade. The tremor caused between US$5 and $25 million in damage,This would cost roughly US$US 5 1970 c million to US$US 25 1970 c million in US-GDP. felt over an area of 8781 km2 on. In Hanoi, North Vietnam, almost 483 km mi on from the epicenter, victims left their homes as the rupture rumbled through the city. Occurring during the height of the Cultural Revolution, it was not widely publicized by the Chinese government for well over a decade. The amount of aid and finances distributed was described by the Beijing Morning Post as "pathetically small". Much of the aid provided to survivors was in "spiritual" form, including Mao Zedong badges and condolence letters. Nevertheless, the earthquake was among the first to be studied over a long term by the Chinese government. It was cited as one of the reasons behind creating the largest earthquake monitoring system in China, 25 years later. Background and tectonics thumb|Fertile plains around Qilu Lake in Tonghai County Yunnan, the epicentral region, is one of the more seismically active Chinese provinces. The earliest earthquake recorded there was in the 9th century; however, moderate to strong ones have been observed since the 15th century. Since the 9th century, 32 earthquakes with a magnitude of 7 or greater have occurred in the province. Shallow strike-slip faulting is a characteristic of Yunnan quakes.Chen & Scawthorn (2002), p. 442. Earthquakes in southwestern Yunnan, such as the 1970 Tonghai event, are less frequent than in other parts of the province. The Red River Fault, the fault on which this quake is alleged to have occurred, has lacked seismological activity as a whole. Red River temblors generally rise at high angles, as shown in a 1962 Ministry of Geology report.Allen et al. (1984), p. 687. Marking in sedimentary rocks indicate that several large earthquakes formed on the fault during the Pleistocene and Holocene epochs.Allen et al. (1984), p. 686. Until this quake, no earthquake above magnitude 7.0 on the Richter scale had occurred on this fault since about 1700, and the fault was believed to be "dead". Since the 1970 Tonghai rupture, it is believed that the Red River fault is instead experiencing a long seismic gap similar to that of the Japan Median Tectonic Line, on which no major temblor has formed since 700 but produced massive ones during the Holocene epoch.Allen et al. (1984), p. 689. Damage and casualties thumb|The city of Gejiu was 97 km on from the epicenter The epicenter of the quake was about 121 km on southwest of Kunming and 97 km on northwest of Gejiu; this area was mainly a tobacco-growing region. Effects of the rupture were felt over an area of 8781 km2 on. In Hanoi, North Vietnam, almost 483 km on from the epicenter, victims left their homes as the rupture rumbled through the city.https://earthquake.usgs.gov/learn/today/index.php?month=1&day=4&submit=View+Date Today in Earthquake History: January 4 United States Geological Survey 16 July 2008 16 November 2008 The earthquake measured 7.1 on the moment magnitude scale. It may have killed more than 15,000 people, making it the third deadliest in China during the 20th century, and injured an additional 26,783.Zchau & Küppers (2003), p. 482. The tremor caused between US$5 to $25 million in damage.https://neic.usgs.gov/neis/eq_depot/2003/eq_030721/index.html Magnitude 6.0 YUNNAN, CHINA 21 July 2003 United States Geological Survey 9 November 2008 12 June 2011 https://web.archive.org/web/20110612012542/http://neic.usgs.gov/neis/eq_depot/2003/eq_030721/index.html dead A Reuters news report, the only one in the immediate aftermath, mentioned the recording of a "severe" quake by Hong Kong's Royal Observatory and cited an unconfirmed report that it might have destroyed part of Kunming.https://www.nytimes.com/1988/11/19/world/chinese-disclose-that-quake-in-1970-killed-about-10000.html Chinese Disclose That Quake In 1970 Killed About 10,000 Kristof Nicholas D. 19 November 1988 The New York Times 8 November 2008 It caused 50 km mi on of visible surface faulting on the Tonghai Fault. There was a maximum horizontal offset of 2.5 m (8 ft) and vertical offset of about 0.5 m (1.5 ft). As a result of inversion techniques, scientists were able to decide that several events comprised the surface faulting. This further confirmed that the earthquake, along with a later earthquake in Yunnan in 1973, corresponded to a fault within the area.Rupture complexity of the 1970 Tonghai and 1973 Luhuo earthquakes, China, from P-wave inversion, and relationship to surface faulting http://bssa.geoscienceworld.org/content/73/6A/1585.abstract Hui-Lan Zhou Clarence R. Allen Hiroo Kanamori Hiroo Kanamori Bulletin of the Seismological Society of America 1983 6a 73 1585–1597 10.1785/BSSA07306A1585 1983BuSSA..73.1585Z subscription Aftermath Scientific study The earthquake was among the first to be studied over a long term by the Chinese government. More than 40 Chinese seismologists, engineers, and geologists visited the disaster zone to conduct research into the cause and damage of the earthquake; some spending as much as a year collecting soil samples and recording other primary research evidence for future study. Such data was collected over a broad area of almost 1,400 towns within the area.Hu et al. (1996), p. 107. Reaction According to the Reuters report, the survivors came together to "fight against the disaster".https://timesmachine.nytimes.com/timesmachine/1970/01/09/118445385.pdf Severe Quake in Yunnan Is Confirmed by Peking Reuters 9 January 1970 The New York Times 30 26 January 2009 Much of the aid provided to survivors was in "spiritual" form. The Chinese government sent tens of thousands of Quotations from Chairman Mao Zedong books and badges in his honor to victims as part of the relief effort, and survivors also received 14,350 sympathy letters. However, the amount of aid and finances distributed was described by the Beijing Morning Post 30 years later as "pathetically small." The details of the earthquake were not widely publicized by Chinese authorities until about 18 years after its occurrence.Kurtenbach Elaine http://docs.newsbank.com/openurl?ctx_ver=z39.88-2004&rft_id=info:sid/iw.newsbank.com:NewsBank:PHIB&rft_val_format=info:ofi/fmt:kev:mtx:ctx&rft_dat=0EB734EF17EACD30&svc_dat=InfoWeb:aggregated5&req_dat=0D0CB579A3BDA420 China finally talking about devastating earthquake of 1970 AO5 The Philadelphia Inquirer NewsBank 8 January 2000 6 November 2008 In China's first decades of Communist rule, its policy was to not disclose natural disasters or accidents unless foreigners were injured. While the Chinese official press had not released a comprehensive report, Reuters and the Royal Hong Kong Observatory both released information soon after the disaster. At the time of the quake, Xinhua News Agency briefly mentioned a smaller magnitude quake but did not provide information on damage or casualties. On 19 November 1988, nearly 19 years later, Chen Zhangli of the State Seismology Bureau, speaking at a news conference for another earthquake that had recently occurred, estimated the death toll of the 1970 quake to be 10,000. He did not give a reason why his government had not previously disclosed this knowledge. Government officials from China released a different estimate in 2000, putting the death toll at 15,621.http://docs.newsbank.com/openurl?ctx_ver=z39.88-2004&rft_id=info:sid/iw.newsbank.com:NewsBank:SLDB&rft_val_format=info:ofi/fmt:kev:mtx:ctx&rft_dat=0EB05209287BEA8F&svc_dat=InfoWeb:aggregated5&req_dat=0D0CB579A3BDA420 St. Louis Post-Dispatch NewsBank 8 January 2000 China breaks silence on devastation from quake 30 years ago 6 November 2008 China published the estimate after a memorial service for survivors and relatives was held in Yuxi on 5 January. A Yuxi Seismology Bureau official noted that the information had been classified for "political reasons" and the death toll estimate had been known among bureaucrats as early as 1997. Twenty-five years after the earthquake, the largest earthquake-monitoring network nationally was established in Yunnan. It set up earthquake offices in every county to prepare for another large rupture. The 1970 Tonghai earthquake was cited as one of the reasons behind creating the monitoring system.China's Largest Earthquake Monitoring System in Yunnan 11 October 1995 Xinhua News Agency HighBeam Research See also List of earthquakes in 1970 List of earthquakes in Yunnan List of earthquakes in China Notes References ISC-GEM Global Instrumental Earthquake Catalogue (1900–2009) http://www.isc.ac.uk/iscgem/index.php ISC 2015 International Seismological Centre Version 2.0 PAGER-CAT Earthquake Catalog https://earthquake.usgs.gov/static/lfs/data/pager/catalogs/ 4 September 2009 United States Geological Survey Version 2008_06.1 Bibliography Reference-Allen-1984 Allen C. R. Clarence Allen (geologist) A. R. Gillespie Han Yuan Kerry E. Sieh Kerry Sieh Zhang Buchun Zhu Chengnan June 1984 Red River and associated faults, Yunnan Province, China; Quaternary geology, slip rates, and seismic hazard Geological Society of America Bulletin 95 6 686–700 http://authors.library.caltech.edu/53723/ 10.1130/0016-7606(1984)95<686:RRAAFY>2.0.CO;2 1984GSAB...95..686A 5 January 2016 16 October 2015 https://web.archive.org/web/20151016220751/http://authors.library.caltech.edu/53723/ dead subscription Reference Chen-2002 Chen Wai-Fah Charles Scawthorn Earthquake Engineering Handbook 2002 CRC Press 978-0-8493-0068-4 Reference-Hu-1996 Hu Yu-Xian Shih Chi Liu Weimin Dong Earthquake Engineering 1996 Taylor & Francis 978-0-419-20590-6 Reference-Zchau-2003 Zschau Jochen Andreas N. Küppers Early Warning Systems for Natural Disaster Reduction 2003 Springer 978-3-540-67962-2 Further reading 10.1785/0120190185 Investigation on the Dynamic Rupture of the 1970 Ms 7.7 Tonghai, Yunnan, China, Earthquake on the Qujiang Fault Bulletin of the Seismological Society of America 2020 Chen Xiaofei Li Zhengbo Zhang Zhenguo Zhang Wenqiang Yu Houyun 110 2 898–919 2020BuSSA.110..898Y 213502598 External links 799712 Category:1970 earthquakes 1970 Tonghai Category:1970 in China Category:January 1970 in Asia Category:Geography of Yuxi Category:1970 disasters in China