On May 21, 2021, a 6.1 magnitude earthquake struck the Dali City, Yunnan, China, at a depth of 10.0 km.[9] Three people died during the quake, while another 32 were injured.[7][8] The earthquake was referred by the Chinese media as the 5.21 earthquake or 2021 Yangbi earthquake.

2021 Dali earthquake
2021 Dali earthquake is located in Yunnan
2021 Dali earthquake
UTC time2021-05-21 13:48:37
ISC event625916004
USGS-ANSSComCat
Local date2021-05-21
Local time21:48 (China Standard Time)
Magnitude6.1 Mw
Depth10.0 km (6.2 mi)
Epicenter25°45′40″N 100°00′29″E / 25.761°N 100.008°E / 25.761; 100.008
FaultRed River Fault
TypeStrike-slip
Areas affectedDali City, Yunnan, China
Max. intensityCSIS VIII[1]

MMI IX (Violent)[2]
ForeshocksMw  5.2[3]
Aftershocks27 above Mw 4.0[4] (Strongest is 5.1 Mw[5])
Casualties3 dead, 32 injured[6][7][8]

Tectonic setting

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Yunnan lies at the southeastern boundary of the Tibetan Plateau where strike-slip faults accommodate crustal rotation resulting from deformation caused by the ongoing collision between the Indian Plate and the Eurasian Plate which formed the Himalayas and the Tibetan Plateau. The presence of active faults make the region prone to moderate to large earthquakes. Major events in Yunnan Province have occurred in 1833, 1974, 1976, 1988 and 2014. The nearest active faults in Dali City are the Xiaojiang Fault and Red River Fault.[citation needed] The Red River Fault caused two deadly earthquakes in 1925 near Dali and another in 1970 in Tonghai county.[10]

Earthquake

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The earthquake was the result of strike-slip faulting at a shallow depth. It had a maximum intensity of IX (Violent) on the Mercalli intensity scale.[9] According to the United States Geological Survey (USGS), the earthquake had a moment magnitude of 6.1 while the China Earthquake Networks Center (CENC) and China Earthquake Administration (CEA) measured the earthquake at 6.4 on the surface-wave magnitude scale.[11] The depth of focus is reported to be 10 km by the USGS and 8 km by the CEA.

Several hours later, an unrelated Mw 7.3 earthquake struck Southern Qinghai province that was felt in the area. [12]

Casualties

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Two fatalities were reported in Yangbi County while another three suffered serious injuries. One of the victims, a truck driver, was killed as a result of a rockfall while another woman in a trapped vehicle had leg injuries.[13] A total of 26 people in the county were injured.[8] In Yongping County, the earthquake killed one person, and left another injured.[14] A 28th injury was reported in Dali City.[15] On May 22, a press release said the number of people injured was brought to 32, with seven in serious condition.[6] Five of the seven who are seriously injured suffered trauma to the head and chest, as well as bone fractures.

Damage

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The earthquake damaged some 12,882 homes in Yangbi County.[8]

See also

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References

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  1. ^ Junju Xie; Zhao An; Lei Fu; Kewei Li; Xiaojun Li; Zengping Wen; Jianwen Cui; Guoliang Lin; Pengfei Wang. "Strong Ground Motions From the 21 May 2021 M6.4 Yangbi Earthquake in Western China" (PDF). researchsquare.com.
  2. ^ Wenkai Chen; Dun Wang; Can Zhang; Qiang Yao; Hongjun Si (2021). "Estimating seismic intensity maps of the 2021 Mw 7.3 Madoi, Qinghai and Mw 6.1 Yangbi, Yunnan, China earthquakes". Journal of Earth Science. 33 (4): 839–846. doi:10.1007/s12583-021-1586-9. S2CID 247246109.
  3. ^ "M 5.2 - 22 km WNW of Dali, China".
  4. ^ "USGS earthquake catalog".
  5. ^ "M 5.1 - 24 km WNW of Dali, China".
  6. ^ a b "云南漾濞6.4级地震致3死32伤 抗震救灾工作有序进行" (in Chinese). Xinhua News Agency. 22 May 2021. Retrieved 27 May 2021.
  7. ^ a b "Two people died in the magnitude 6.4 earthquake in Yangbi, Yunnan" (in Chinese). Xinhua Net. 21 May 2021. Retrieved 21 May 2021.
  8. ^ a b c d Qian Zhongbing, ed. (21 May 2021). "1 dead and 22 injured in the Yangbi earthquake in Yunnan" (in Chinese). Xinhua Net. Retrieved 21 May 2021.
  9. ^ a b "M 6.1 - 28 km NW of Dali, China". United States Geological Survey. 21 May 2021. Retrieved 21 May 2021.
  10. ^ Zhao Yuhe; Yang Xiu Dazhen; Lu Xueli (22 May 2021). "揪心!雲南、青海兩地深夜發生強震,已有傷亡" (in Chinese). Beijing Sina.com. Archived from the original on 22 May 2021. Retrieved 22 May 2021.
  11. ^ China Earthquake Administration. "A magnitude 6.4 earthquake occurred in Yangbi County, Dali Prefecture, Yunnan Province at 21:48 on May 21". cea.gov.cn. China Earthquake Administration. Retrieved 21 May 2021.
  12. ^ "M 7.4 - Southern Qinghai, China". earthquake.usgs.gov. Retrieved 21 May 2021.
  13. ^ Zhang Qi (22 May 2021). "In the Dali earthquake in Yunnan, a truck driver was hit by a rolling stone and killed, and 6 others were injured" (in Chinese). Chutian Metropolis Daily News. Retrieved 22 May 2021.
  14. ^ "云南大理州漾濞地震已致3人死亡,28人受伤" (in Chinese). Sohu. 22 May 2021. Retrieved 22 May 2021.
  15. ^ CCTV News (21 May 2021). Zhou Zijing (ed.). "The magnitude 6.4 earthquake in Yangbi, Yunnan has killed 3 people and injured 27". The Paper. Retrieved 21 May 2021.