2003 Dayao earthquake

Earthquake in Yunnan, China
25°58′N 101°15′E / 25.96°N 101.25°E / 25.96; 101.25[1]TypeStrike-slip[2]Areas affectedChinaMax. intensityMMI VII (Very strong)Casualties19 dead, 644 injured

The 2003 Dayao earthquake occurred on July 21, at 23:16:33 CST. The epicenter of the moment magnitude 5.9 earthquake was in Dayao County in the mountainous area of central Yunnan, China. At least 19 people were killed, 644 were injured,[3] and 8,406 families became homeless. The quake also caused $75 million USD in damage.[4][2]

Tectonic setting

Yunnan is located at the southeastern edge of the Tibetan Plateau, where the Indian Plate is colliding north–northeast into the Eurasian Plate (Asia). The continental deformation is accommodated by major faults in the area, mostly of strike-slip movement. The Indian Plate pushes into Asia, uplifting the Tibetan Plateau and causes it rotate clockwise, along the Xianshuihe fault system. This deformation spreads into Yunnan, where active strike-slip faulting occurs.[5]

Earthquake

The earthquake measured 6.1 on the surface-wave magnitude scale. It was the first of two earthquakes in the same area that year. In October, an Ms  6.2 (Mw  5.6) earthquake struck nearby, killing three people.[6] The July earthquake occurred as a result of shallow strike-slip faulting.[7] Coulomb stress transfer from the July quake increased the chance of failure on nearby faults which triggered the October quake.[8]

Impact

The quake occurred when most victims were asleep. In the village of Ganghe, at least 11 people were killed due to collapsing homes made of mud. An aftershock on July 23 caused additional collapses and injured 51 people.[9] In Songziyuan village, many homes were destroyed. Large fissures opened in roads and landslides blocked passing vehicles. At least one person died in the village. A total of 264,474 houses collapsed, leaving many homeless.[10]

See also

References

  1. ^ a b c d ISC-OB Event 7003234 [IRIS].
  2. ^ a b ANSS. "M 6.0 - 75 km SSW of Dadukou, China". Comprehensive Catalog. U.S. Geological Survey.
  3. ^ Wang, Wei Jun; Chen, Ling; Chen, Qi Fu; Liu, Jie (2007). "2003 年大姚地震震中区的速度和衰减结构" [Velocity and attenuation structures in the focal area of 2003 Dayao earthquakes]. Chinese Journal of Geophysics (in Chinese). 50 (3): 770–779. Archived from the original (PDF) on April 1, 2022.
  4. ^ National Geophysical Data Center / World Data Service (NGDC/WDS): NCEI/WDS Global Significant Earthquake Database. NOAA National Centers for Environmental Information (2003). "Significant Earthquake Information". NOAA National Centers for Environmental Information. doi:10.7289/V5TD9V7K. Retrieved 2022-04-01. {{cite journal}}: Cite journal requires |journal= (help)
  5. ^ Wang, Fan; Wang, Min; Wang, Yanzhao; Shen, Zheng-Kang (2015). "Earthquake Potential of the Sichuan-Yunnan Region, Western China". Journal of Asian Earth Sciences. 107. Elsevier: 232–243. Bibcode:2015JAESc.107..232W. doi:10.1016/j.jseaes.2015.04.041.
  6. ^ ANSS. "M 5.6 - Yunnan, China". Comprehensive Catalog. U.S. Geological Survey.
  7. ^ Wang, Xiaoshan; Feng, Xiangdong; Diao, Guiling; Wang, Libing; Cai, Lingling (2009). "Difference between focal mechanisms of Dayao earthquake doublet sequence" [Difference between focal mechanisms of Dayao earthquake doublet sequence]. Earthquake Science (in Chinese). 22 (6): 667–673. Bibcode:2009EaSci..22..667W. doi:10.1007/s11589-009-0667-0. S2CID 128413530.
  8. ^ Xu, Xiaofeng; Wan, Yongge; Wang, Huilin (2011). "Stress value in 2003 Dayao MS6.1 earthquake source region". Earthquake Science. 24 (4): 343–350. Bibcode:2011EaSci..24..343X. doi:10.1007/s11589-011-0797-z. S2CID 129935225.
  9. ^ Liu, Ben-yu; Miao, Sheng; Ye, Liao-yuan; Xiao, Mei-ling (2006). "Damage of village buildings in recent Yunnan earthquakes". 4th International Conference on Earthquake Engineering Taipei, Taiwan (266).
  10. ^ ACT Alliance (29 July 2003). "ACT Alert 1/2003 China Dayao Earthquake". ReliefWeb. Retrieved 1 April 2022.

External links

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