1974 Zhaotong earthquake

Earthquake in China

1974 Zhaotong earthquake

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UTC time| 1974-05-10 19:25:16
ISC event| 748061
USGS-ANSS| ComCat
Local date| May 11, 1974 (1974-05-11)
Local time| 03:25:16
Magnitude| 7.1 Ms
Depth| 14 km (8.7 mi)[1]
Epicenter| 28°14′N 104°01′E﻿ / ﻿28.24°N 104.01°E﻿ / 28.24; 104.01[2]
Areas affected| China, Yunnan, Sichuan
Max. intensity| MMI IX (Violent)
Casualties| 1,641–20,000[2][3]

The 1974 Zhaotong earthquake occurred at 3:25 in the morning local time on 11 May 1974, with a Coordinated Universal Time (UTC) time of 19:25:16 on 10 May. It had a magnitude that was measured at 7.0 on the moment magnitude scale[4] and 7.1 on the surface-wave magnitude scale. It had a maximum perceived intensity of IX (Violent) on the Mercalli intensity scale. The epicenter was located in Zhaotong prefecture in Yunnan province and it caused between 1,641 and 20,000 deaths.

## Earthquake

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The earthquake has been ascribed to slip on a thrust fault trending north–south with a dip of 60° to the east, from geodetic data analysis.[5] It has also been interpreted to result from strike-slip faulting along a steeply-dipping NW-SE trending fault.[4] The isoseismal lines for the earthquake were poorly defined, due to variations both in topography and ground conditions.[1]

The earthquake consisted of more than ten separate sub-events. The sequence began with a few shocks in the first two to three seconds with magnitudes less than 5. These were followed by several shocks approaching magnitude 7 over a period of about a minute. The areal distribution of the individual shocks showed no progression along the fault plane as would be expected with a propagating fracture.[6]

The earthquake triggered many landslides in the epicentral area. The bedrock geology in the area contains rocks of almost all ages from Neoproterozoic through to Quaternary. Landslides were mainly confined to areas that experienced intensities of VII or greater and had slopes of moderate dip (26°-45°). In all but one case, the landslides involved Quaternary material, the exception being a slide that was controlled by bedding planes in a Permian limestone. Rock avalanches occurred on steeper slopes, particularly affecting jointed and weathered Permian limestone and Triassic sandstone/shale sequences.[7]

## Damage

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An area of about 400,000 square kilometres was affected by the earthquake. 28,000 houses collapsed and a further 38,000 were damaged. Houses with wooden frames in the epicentral area remained undamaged.[8] The number of deaths reported varies from 1,641 to 20,000[2][3] with a further 1,600 injured.

The largest landslide formed a dam up to 30 metres (98 ft) high across the Yangtze River, turning the valley above it into a lake.[8]

## See also

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* List of earthquakes in 1974
* List of earthquakes in Yunnan
* List of earthquakes in Sichuan
* List of earthquakes in China

## References

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1. ^ a b Hu, Y.; Liu S.C.; Dong W. (1996). "Earthquakes in China". Earthquake Engineering. Taylor & Francis. pp. 107–108. ISBN 9780419205906. Retrieved 17 July 2012.
2. ^ a b c National Geophysical Data Center. "Comments for the Significant Earthquake". Retrieved 17 July 2012.
3. ^ a b Utsu, T. R. (2002), "A List of Deadly Earthquakes in the World: 1500–2000", International Handbook of Earthquake & Engineering Seismology, Part A, Volume 81A (First ed.), Academic Press, p. 708, ISBN 978-0124406520
4. ^ a b Zhuo, Y.; Kanamori H. (1987). "Regional variation of the short-period (1 to 10 second) source spectrum" (PDF). Bulletin of the Seismological Society of America. 77 (2): 514–529. Bibcode:1987BuSSA..77..514Z. doi:10.1785/BSSA0770020514. Archived from the original (PDF) on 2013-12-11. Retrieved 18 July 2012.
5. ^ Zhu, C.-N.; Chen C.-Z. (1976). "The Rupture Mechanism of the Zhaotong earthquake of 1974 in Yunnan Province". Chinese Journal of Geophysics. 19 (4): abstract only. Archived from the original on 2013-12-12. Retrieved 17 July 2012.
6. ^ Tseng, J.S.; Shi J.S. (1978). "Source multiplicity of the main shock of the Yong Shan-Da Guan Yunnan Earthquake of May 10, 1974". Acta Geophysica Sinica. 21: 160–173. Archived from the original on 11 December 2013. Retrieved 18 July 2012.
7. ^ Chen, X.L.; Zhou Q., Ran H. & Dong R. (2012). "Earthquake-triggered landslides in southwest China". Natural Hazards and Earth System Sciences. 12 (2): 351–363. Bibcode:2012NHESS..12..351C. doi:10.5194/nhess-12-351-2012.
8. ^ a b Museum of Earthquakes. "Earthquakes in China: Typical earthquakes". Computer Network Information Center of Chinese Academy of Sciences. Retrieved 21 September 2013.

## External links

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* The International Seismological Centre has a bibliography and/or authoritative data for this event.

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← Earthquakes in 1974 →

* Izu Peninsula (6.5, May 8)
* Zhaotong (7.1, May 10) †
* Lima (8.1, Oct 3) †
* Lesser Antilles (6.9, Oct 8)
* Pattan (6.2, Dec 28) †‡

† indicates earthquake resulting in at least 30 deaths
‡ indicates the deadliest earthquake of the year

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Earthquakes in China

Historical|

* 1038 Dingxiang
* 1290 Chihli (Inner Mongolia)
* 1303 Hongdong, Shanxi
* 1536 Xichang, Sichuan
* 1556 Shaanxi
* 1604 Quanzhou, Fujian
* 1605 Guangdong
* 1626 Lingqiu, Shanxi
* 1654 Tianshui, Gansu
* 1668 Tangcheng, Shandong
* 1679 Beijing, Hebei
* 1695 Linfen, Shanxi
* 1709 Zhongwei
* 1718 Tongwei, Gansu
* 1733 Dongchuan, Yunnan
* 1738 Dangjiang, Qinghai
* 1739 Yinchuan–Pingluo, Ningxia
* 1786 Kangding-Luding, Sichuan
* 1815 Pinglu, Shanxi
* 1830 Cixian, Hebei
* 1833 Kunming, Yunnan
* 1850 Xichang, Sichuan
* 1879 Wudu, Gansu
* 1889 Chilik, Xinjiang

20th century|

* 1902 Kashgar, Xinjiang
* 1906 Manas, Xinjiang
* 1913 Eshan, Yunnan
* 1918 Shantou, Guangdong
* 1920 Haiyuan, Ningxia
* 1923 Renda, Sichuan
* 1925 Dali, Yunnan
* 1927 Gulang, Gansu
* 1931 Fuyun, Xinjiang
* 1932 Changma
* 1933 Diexi, Sichuan
* 1936 Lingshan, Guangxi
* 1937 Heze, Shandong
* 1947 Assam
* 1948 Litang, Sichuan
* 1950 Assam–Tibet
* 1952 Damxung
* 1955 Kangding, Sichuan
* 1955 Yuzha, Sichuan
* 1966 Xingtai, Hebei
* 1969 Bohai Sea
* 1969 Yangjiang, Guangdong
* 1970 Tonghai, Yunnan
* 1973 Luhuo, Sichuan
* 1974 Zhaotong, Yunnan
* 1975 Haicheng, Liaoning
* 1976 Longling, Yunnan
* 1976 Tangshan, Hebei
* 1976 Songpan–Pingwu, Sichuan
* 1981 Dawu, Sichuan
* 1983 Heze, Shandong
* 1985 Luquan, Yunnan
* 1985 Wuqia, Xinjiang
* 1988 Lancang–Gengma, Yunnan
* 1990 Gonghe, Qinghai
* 1994 Taiwan Strait
* 1995 Menglian, Yunnan
* 1995 Wuding, Yunnan
* 1996 Lijiang, Yunnan
* 1996 Baotou, Inner Mongolia
* 1997 Jiashi, Xinjiang
* 1997 Manyi, Tibet
* 1998 Zhangbei
* 1998 Ninglang, Yunnan
* 2000 Yunnan

21st century|

* 2001 Kunlun
* 2003 Bachu, Xinjiang
* 2003 Dayao
* 2003 Zhaosu, Xinjiang
* 2005 Ruichang, Jiangxi
* 2006 Yanjin, Yunnan
* 2008 Sichuan
* 2008 Yingjiang, Yunnan
* 2008 Panzhihua, Sichuan
* 2008 Damxung, Tibet
* 2009 Xinjiang
* 2009 Yunnan
* 2010 Yushu, Qinghai
* 2011 Yunnan
* 2011 Myanmar
* 2012 Yangzhou, Jiangsu
* 2012 Zhaotong, Yunnan
* 2013 Lushan, Sichuan
* 2013 Dingxi, Gansu
* 2014 Yutian, Xinjiang
* 2014 Yingjiang, Yunnan
* 2014 Ludian, Yunnan
* 2014 Jinggu, Yunnan
* 2014 Kangding, Sichuan
* 2015 Pishan, Xinjiang
* 2017 Taxkorgan, Xinjiang
* 2017 Jiuzhaigou, Sichuan
* 2017 Jinghe, Xinjiang
* 2019 Changning, Sichuan
* 2020 Kashgar, Xinjiang
* 2020 Qiaojia, Yunnan
* 2021 Dali, Yunnan
* 2021 Maduo, Qinghai
* 2021 Luxian, Sichuan
* 2022 Menyuan, Qinghai
* 2022 Ya'an, Sichuan
* 2022 Luding, Sichuan
* 2023 Jishishan
* 2024 Uqturpan

By province|

* Sichuan
* Yunnan

Organizations|

* China Meteorological Administration
* China Earthquake Administration
* China Earthquake Networks Center
* China Geological Survey
* China International Search and Rescue Team

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