On June 1, 2022, a moment magnitude (Mw ) 5.8 or surface-wave magnitude (Ms ) 6.1 earthquake struck Lushan County in Ya'an, Sichuan Province, China.[1] At least four people were killed and 42 were injured.[3] The earthquake had a maximum intensity of VIII on the China seismic intensity scale, causing damage to many homes and triggering rockslides.

2022 Ya'an earthquake
2022年芦山县地震
2022 Ya'an earthquake is located in China
2022 Ya'an earthquake
UTC time2022-06-01 09:00:08
ISC event624424142
USGS-ANSSComCat
Local date1 June 2022
Local time17:00 CST (UTC+8)
Magnitude5.8 Mw(USGS)
6.1 Ms(CENC)
Depth12 km (7.5 mi) (USGS)
17 km (11 mi) (CENC)
Epicenter30°24′58″N 102°59′20″E / 30.416°N 102.989°E / 30.416; 102.989
TypeReverse fault[1]
Areas affectedSichuan
Max. intensityCSIS VIII[2]
Casualties4 dead, 42 injured

Tectonic setting

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A map of the India-Asia deformation zone with active faults in the region.

The active plate convergence between the Indian and Eurasian plates along the Main Himalayan Thrust results in widespread intracontinental deformation within Central Asia. As the Indian plate collides with the Eurasian plate, part of the Eurasian plate is uplifted and deformed, resulting in the formation of the Tibetan Plateau. The internal deformation is accommodated along strike-slip and to a lesser extent, thrust faults. Major faults, including the Xianshuihe fault system, Kunlun Fault, Altyn Tagh fault, and Longmenshan Fault, accommodate this deformation. The deadly 2008 and 2013 earthquakes occurred due to thrust faulting along the Longmenshan Fault.[4] Between the rupture areas there exists a seismic gap with the potential to generate a destructive earthquake in the future.[5]

Earthquake

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The earthquake occurred at 17:00 local time. It had a moment magnitude of 5.8 and occurred at a depth of 12 km (7.5 mi), according to the United States Geological Survey (USGS). The China Earthquake Networks Center (CENC) measured the earthquake at a surface-wave magnitude (Ms ) of 6.1 at a depth of 17 km (11 mi).[6] A smaller magnitude 4.5 (mb  5.3[7]) earthquake occurred three minutes later.[8] The Sichuan Earthquake Administration said that this event was an aftershock of the magnitude 7.0 earthquake that occurred in April 2013, which killed nearly 200 people.[9] Another earthquake, with a magnitude of 4.9, occurred nearby in May, damaging 468 houses.[10][11][12][13]

Both earthquakes occurred on the Shuangshi-Dachuan Fault. The epicenter, according to earthquake experts from China, was located 2 km from the fault. The Shuangshi-Dachuan Fault is part of the larger Longmenshan Fault structure, which forms the eastern boundary of the Bayan Har block. A focal mechanism analysis suggest the 2022 earthquake occurred due to thrust faulting.[14] Experts from the CENC said it is unlikely that this earthquake would be a foreshock to a larger event.[15]

Impact

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Damage to the walls of the Taiping Middle School in Lushan County.

A preliminary survey of the affected area determined that 135 homes in Ya'an and 4,374 in Lushan were damaged.[16] Some parked vehicles in Baoxing County were crushed by falling boulders. Some nearby buildings and five hydropower stations were also damaged.[17][18] In Taiping, damage was minimal; most buildings only suffered cracked or partially collapsed walls. Many houses were reconstructed to seismic codes after the 2008 and 2013 earthquakes.[19] Video footage showed damaged buildings and debris on streets and large boulders blocking roads in the mountainous area.[20] At least three county roads and China National Highway 351 were damaged by rockfalls.[21] Officials in Sichuan said that there were no reports of collapsed buildings.[22] The earthquake disrupted the supply of electricity to over 49,000 homes. Repairs were made and power supply was resumed to at least 18,000 homes.[23]

All four fatalities and 42 injured individuals were reported in nearby Baoxing County.[3] Some of the injured were transported to nearby hospitals for treatment. The Ya'an Municipal Party Committee Office said that the four victims were fatally struck by falling rocks.[24]

The earthquake was felt with an intensity of at least VI over an estimated 3,887 km2 area. A maximum liedu of VIII was observed in Taiping, Shuangshi, Lingguan, and Muping. The intensity covered a 76 km × 65 km (131 km2) area. Intensity VII was felt across a 979 km2 area. In Chengdu, the earthquake was felt VI.[2]

Emergency response

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At least nine seconds of advanced warning was given to Ya'an, 44 km from the epicenter, and in Meishan, located 94 km from the epicenter. Warnings were also issued in Chengdu and Garzê Tibetan Autonomous Prefecture.[25] An estimated 10 million residents around the earthquake epicenter received the early warning.[26] As a precautionary measure, railway services at Chengdu East railway station were suspended and affected passengers were given a refund.[27]

A Level 3 emergency response was ordered by the Chinese government on the four-level emergency response system. At least 4,500 personnel consisting of medical and emergency responders were dispatch to the epicenter area.[20] In Meishan, 15 firetrucks and 60 personnel were dispatched. Local fire and rescue services were also activated.[28] Staff at the Red Cross Society of China in Sichuan were mobilized to the affected area to distribute relief supplies.[29] Officials from the Sichuan Provincial Department of Housing and Urban-Rural Development said that an investigation would be carried out to assess the damage.[30] On June 2, electrical services was restored to over 48,000 households while an estimated 3,339 were still awaiting restoration.[31]

A total of 12,772 residents were affected and displaced.[21] Affected residents in Lushan were resettled in tents at a nearby school in Taiping. The school also served as a supply distribution center. Relief workers and resettled villagers reported that the walls of the school had cracks and shattered.[32]

See also

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References

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  1. ^ a b "M 5.9 – 45 km W of Linqiong, China". United States Geological Survey. 1 June 2022. Archived from the original on 1 June 2022. Retrieved 1 June 2022.
  2. ^ a b Xiang Nan, ed. (4 June 2022). "中国地震局发布四川芦山6.1级地震烈度图" [The China Earthquake Administration released the intensity map of the Sichuan Lushan earthquake with a magnitude of 6.1] (in Chinese). China Earthquake Administration. Archived from the original on 3 August 2022. Retrieved 5 June 2022.
  3. ^ a b Jia Yichao; Fan Jianfeng (3 June 2022). Chen Zhouying (ed.). "四川芦山"6·1"地震造成4人死亡42人受伤 14427人受灾" [Sichuan Lushan "6.1" earthquake caused 4 deaths, 42 injuries, 14,427 people affected]. China Central Television. Hangzhou Net. Archived from the original on 3 June 2022. Retrieved 3 June 2022.
  4. ^ Becky Oskin (21 April 2013). "What Caused The Deadly China Earthquake?". Live Science. Archived from the original on 6 October 2021. Retrieved 1 June 2022.
  5. ^ Shao, Chongjian; Liu, Shao; Li, Yong; Zhou, Rongjun; Wang, Shiyuan; Long, Jianyu; Yan, Zhaokun; Yan, Mei (2019). "Paleoseismic events on the Shuangshi-Dachuan fault of the seismic gap, Longmen Shan thrust belt, eastern margin of the Tibetan Plateau". Journal of Asian Earth Sciences. 169. Elsevier: 1–10. Bibcode:2019JAESc.169....1S. doi:10.1016/j.jseaes.2018.10.010. S2CID 133664788. Archived from the original on 2022-06-01. Retrieved 2022-06-01.
  6. ^ "6月1日17时0分在四川雅安市芦山县发生6.1级地震" [At 17:00 on June 1, an earthquake of magnitude 6.1 occurred in Lushan County, Ya'an City, Sichuan Province.] (in Chinese). China Earthquake Networks Center. 1 June 2022. Archived from the original on 5 June 2022. Retrieved 1 June 2022.
  7. ^ "M 5.3 – WESTERN SICHUAN, CHINA – 2022-06-01 09:03:07 UTC". emsc-csem.org. European-Mediterranean Seismological Centre. 1 June 2022. Archived from the original on 1 June 2022. Retrieved 2 June 2022.
  8. ^ Zhang Zhuxin, ed. (1 June 2022). "芦山6.1级地震伤亡情况通报" (in Chinese). People's Government of Sichuan Province. Archived from the original on 5 June 2022. Retrieved 1 June 2022.
  9. ^ "四川地震局:此次四川芦山6.1级地震属2013年"4·20"7.0级地震余震" [Sichuan Earthquake Administration: The Sichuan Lushan M6.1 earthquake is an aftershock of the 2013 "4.20" M7.0 earthquake]. China Central Television (in Chinese). China News Service. 1 June 2022. Archived from the original on 5 June 2022. Retrieved 1 June 2022.
  10. ^ "M 4.9 – 74 km E of Kangding, China". United States Geological Survey. 20 May 2022. Archived from the original on 3 August 2022. Retrieved 20 May 2022.
  11. ^ "四川汉源4.8级地震:消防救援队伍解除地震灾害二级响应". k.sina.com.cn (in Chinese). 20 May 2022. Archived from the original on 2022-06-02. Retrieved 2022-06-01.
  12. ^ "Sichuan Hanyuan earthquake of magnitude 4.8: fire rescue team relieves secondary response to earthquake disaster" (in Chinese). 20 May 2022. Archived from the original on 2 June 2022. Retrieved 20 May 2022.
  13. ^ "专家称汉源地震是2013年雅安地震余震,为何9年后仍有余震?" [Experts say that the Hanyuan earthquake was an aftershock of the 2013 Ya'an earthquake. Why are there still aftershocks 9 years later?]. Sohu (in Chinese). 20 May 2022. Archived from the original on 20 May 2022. Retrieved 20 May 2022.
  14. ^ "四川芦山县发生6.1级地震 专家:原震区近几日发生更大地震可能性不大" [A 6.1-magnitude earthquake occurred in Lushan County, Sichuan Expert: It is unlikely that a larger earthquake will occur in the original earthquake area in recent days]. Shanghai Securities Journal (in Chinese). 1 June 2022. Archived from the original on 1 June 2022. Retrieved 1 June 2022.
  15. ^ Xue Tao, ed. (1 June 2022). "专家:短期内芦山余震区再次发生更大地震的可能性不大" [Expert: It is unlikely that a larger earthquake will occur in the Lushan aftershock area in the short term]. Xinhua News Agency. Archived from the original on 5 June 2022. Retrieved 1 June 2022.
  16. ^ "四川雅安芦山6.1级地震:174名专家开展房屋建筑等安全应急评估工作" [Sichuan Ya'an Lushan earthquake of magnitude 6.1: 174 experts carry out safety emergency assessment work such as housing construction]. Qianlong.com. 2 June 2022. Archived from the original on 2 June 2022. Retrieved 2 June 2022.
  17. ^ "四川雅安地震增至4死41傷 多車遭滾落巨石擊中 (15:28)". China Central Television (in Chinese). Ming Pao. 2 June 2022. Archived from the original on 5 June 2022. Retrieved 2 June 2022.
  18. ^ "Powerful quake in China's Sichuan affects over 13,000 people, damages five hydropower projects". India Today. Beijing. Press Trust of India. 2 June 2022. Archived from the original on 2 June 2022. Retrieved 3 June 2022.
  19. ^ "直击雅安震中太平镇:房屋大多损伤较小,全镇居民住进安置点". Yangtse Evening Post (in Chinese). 2 June 2022. Archived from the original on 5 June 2022. Retrieved 2 June 2022.
  20. ^ a b Wang, Amber (1 June 2022). "Four dead as twin quakes shake Chinese city, epicentre of deadly 2013 shock". South China Morning Post. Archived from the original on 1 June 2022. Retrieved 1 June 2022.
  21. ^ a b "四川芦山发生6.1级地震 已转移安置群众12722人" [A 6.1-magnitude earthquake hit Lushan, Sichuan, and 12,722 people have been transferred and resettled]. China Central Television (in Chinese). Xiamen Net. 2 June 2022. Archived from the original on 2 June 2022. Retrieved 2 June 2022.
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  23. ^ "四川芦山地震影响4.9万多户用电 已恢复1.8万多户供电" [More than 49,000 households were affected by the Lushan earthquake in Sichuan, and power has been restored to more than 18,000 households]. cyzone.cn (in Chinese). 2 June 2022. Archived from the original on 3 August 2022. Retrieved 2 June 2022.
  24. ^ Xue Tao, ed. (1 June 2022). "四川雅安地震已造成4人死亡" [Four dead in Sichuan Ya'an earthquake] (in Chinese). Xinhua News Agency. Archived from the original on 1 June 2022. Retrieved 1 June 2022.
  25. ^ "四川雅安地震发生时第4秒发出预警 预警触达数千万人" [An early warning was issued in the 4th second of the Ya'an earthquake in Sichuan, reaching tens of millions of people]. Shanghai Securities Journal (in Chinese). 1 June 2022. Archived from the original on 1 June 2022. Retrieved 1 June 2022.
  26. ^ Ding Peng; Xie Mao; Yao Yun (2 June 2022). Zhang Jiameng (ed.). "4年发生多次地震 雅安所属的龙门山断裂带为何日渐活跃?专家解读" (in Chinese). China Business Network. Archived from the original on 5 June 2022. Retrieved 2 June 2022.
  27. ^ "四川雅安市地震增至4死14傷成都東站列車停運" [Sichuan Ya'an earthquake increases to 4 dead, 14 injured, trains at Chengdu East Railway Station suspended]. RTHK (in Chinese). 1 June 2022. Archived from the original on 1 June 2022. Retrieved 1 June 2022.
  28. ^ "芦山6.1级地震 眉山消防15车60人正前往震中". Sichuan News Network (in Chinese). Yunnan.cn. 1 June 2022. Archived from the original on 1 June 2022. Retrieved 1 June 2022.
  29. ^ "中国红十字会总会紧急支援四川芦山地震灾区" [The Red Cross Society of China urgently supports the earthquake-stricken area in Lushan, Sichuan]. Red Cross Society of China. 1 June 2022. Archived from the original on 5 June 2022. Retrieved 1 June 2022.
  30. ^ Yang Lan (2 June 2022). Liu Bo (ed.). "四川省住建厅:芦山6.1级地震灾区房屋建筑和基础设施受损情况正在摸排中" [Sichuan Provincial Department of Housing and Urban-rural Development: The damage to buildings and infrastructure in the earthquake-stricken area of Lushan 6.1 is under investigation]. thecover.cn (in Chinese). Sichuan Online. Archived from the original on 5 June 2022. Retrieved 2 June 2022.
  31. ^ Xiao Xiao; Liu Liang, eds. (3 June 2022). "雅安地震灾区已恢复4.8万余户供电" [More than 48,000 households in Ya'an earthquake-stricken area have been restored to power] (in Chinese). China Central Television. Xinhua News Agency. Archived from the original on 3 June 2022. Retrieved 3 June 2022.
  32. ^ Fu Xingshuai, ed. (2 June 2022). "四川雅安芦山地震现场见闻:太平中学安置点的不眠夜" (in Chinese). dzwww.com. Archived from the original on 1 June 2022. Retrieved 2 June 2022.
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