August 8, 2017 Earthquake: Aba, Sichuan Province, China

The August 8, 2017, M 6.5 earthquake in northern Sichuan, China, occurred as the result of shallow strike-slip faulting in the interior of the Eurasia plate. Focal mechanism solutions indicate the event occurred on either a southeast striking left-lateral fault or on a southwest striking right-lateral fault. This earthquake occurred several hundred kilometers to the northeast of the convergent India:Eurasia plate boundary, where the India plate is moving northward with respect to Eurasia at a rate of approximately 46 mm/yr. This convergence drives the uplift of the Himalaya Mountains and the Tibetan Plateau, a broad region of thickened and uplifted crust, at a rate of approximately 10 mm/yr. The uplifted Tibetan Plateau is spreading to the east and, as a result, is an area of east-west extension and eastward crustal motion within a larger region of generally north-south convergence. At the edge of the plateau to the east of this earthquake, Tibetan crust is converging with the strong crust underlying the Sichuan Basin and southeastern China. The August 8th earthquake likely reflects the interplay among these major tectonic forces. The region within 250 km of the August 8, 2017, earthquake has experienced 12 events of M6+ over the past century. Most notable in the recent past was the May 12, 2008 M 7.9 Chengdu or Sichuan earthquake, just under 250 km to the south of the August 8, 2017 event. That 2008 earthquake resulted in over 69,000 fatalities and close to 400,000 injuries, destroying over 5 million buildings and affecting over 45 million people across western China. The 2008 earthquake and its prominent aftershock sequence occurred on the Longmenshan fault zone, a prominent structure along the range front to the south and southeast of the 2017 earthquake. In August 1976, three large earthquakes of M 6.9, M 6.4 and M 6.7 struck the region around 50 km to the southeast of today's earthquake. Perhaps due to the relative remoteness of this region, the 1976 earthquakes are not known to have caused any damage or fatalities. At least 23 people killed, 493 injured and 31,500 displaced; many buildings damaged; power outages and landslides occurred in Jiuzhaigou. Yaan, Sichuan, China - CDI: 5; Xichang, Sichuan, China - CDI: 4; Lanzhou, Gansu, China - CDI: 4; Yinchuan, Ningxia, China - CDI: 4; Xian, Shaanxi, China - CDI: 4 (ref #13456)

The 6.5-magnitude earthquake struck Sichuan province late on Tuesday, tearing cracks in mountain highways, triggering rockslides, damaging buildings and sending panicked residents and tourists fleeing into the open. The quake killed at least 19 people and injured 247, 40 of them seriously, according to the local government of Aba prefecture where the epicentre was located. (ref #11865)

The death toll from an earthquake that scarred a scenic region of southwest China's Sichuan province rose to 24 on Friday (Aug 11), state media said, as authorities found more bodies. A total of 493 were injured in Tuesday's 6.5-magnitude quake, including 45 in serious condition […] The Aba prefecture emergency response office earlier said in a statement that more bodies were found inside a bus in a river valley in Zhangzha. It did not give more details about what had happened to the vehicle. (ref #11867)

The latest bulletin from Jiuzhaigou Earthquake Relief Headquarters confirmed that, by 8 p.m. on August 13, the earthquake had affected 17 townships and 120 villages in varying degrees and approximately 10,910 houses were seriously affected while 44,129 people were generally affected, causing 25 people died and 525 injured. (ref #11975)

500 million USD in losses. 100 homes destroyed, >72,500 damaged. Roads damaged. Deaths: 29. Injured: 525. (ref #12078)

29 deaths, 525 injured, 500 million USD total damages. (ref #1250)

1.19 billion economic loss (reference #13727)