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1927 Gulang earthquake

1927 Gulang earthquake
1927 Gulang earthquake is located in Tibetan Plateau
1927 Gulang earthquake
UTC time1927-05-22 22:32:49
ISC event909273
USGS-ANSSComCat
Local dateMay 23, 1927 (1927-05-23)
Local time06:32
Magnitude7.6 Mw
Epicenter37°23′N 102°19′E / 37.39°N 102.31°E / 37.39; 102.31
FaultHaiyuan Fault
Areas affectedGansu, Republic of China
Xining
Max. intensityMMI XI (Extreme)
Casualties40,912
Tectonic setting of the Tibetan Plateau showing main fault zones

The 1927 Gulang earthquake occurred at 06:32 a.m. on 23 May (22:32 UTC on 22 May). This 7.6 magnitude event had an epicenter near Gulang, Gansu in the Republic of China. There were 40,912 deaths.[1] It was felt up to 700 km (435 mi) away.[2]

Geology

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The continental collision between the Indian plate and the Eurasian plate has formed the Himalayas and the large uplifted area of the Tibetan Plateau. The northeastern part of Tibet is affected by the eastward lateral spreading of the Tibetan Plateau. This spreading is accommodated by a series of sinistral (left-lateral) strike-slip faults, including the Altyn Tagh, Haiyuan, Kunlun and Xianshuihe faults, combined with thrusting on the Longmenshan fault. The earthquake ruptured the complex thrust fault system in the Qilian Mountains transpressional zone, formed at a restraining bend on the Haiyuan fault.[3] Another segment of the Haiyuan fault was responsible for the 1920 Haiyuan earthquake.[4]

Damage

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Monseigneur Theodor Buddenbrock conducts missionary work in China 1927

In the area of greatest intensity, all cave dwellings and 90% of houses were destroyed. In Gulang, almost the only thing left standing was a 20 m (66 ft) long section of the city walls and some decorated archways. In Gulang county 4,000 people and 30,000 domestic animals were killed. In Wuwei, most of the city walls collapsed as did many temples, towers and civilian houses, 35,000 people and 200,000 horses and oxen were killed. In the area around Yongchang many primary schools, forts, stockaded villages and temples were destroyed, killing 809 people. In Shandan County more than 5,800 houses were destroyed and many cave dwellings collapsed, leaving 886 people dead.[1]

The ground was extensively fissured, with fissures up to 14 km (8.7 mi) in length, 6–13 m (20–43 ft) wide and 7 m (23 ft) deep. A large landslide at Dongchuan buried several villages and blocked the road for a year.[1]

Scenes of devastation following the 1927 Gulang earthquake

Characteristics

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The magnitude of this earthquake has been variously calculated as 7.6 on the moment magnitude scale and 8.0–8.3 on the surface-wave magnitude scale.[1] The earthquake was the result of thrust and strike-slip faults rupturing simultaneously. Three zones of surface ruptures were associated with the earthquake. Left-lateral displacements of 2.4–7.5 m (7 ft 10 in – 24 ft 7 in) occurred along a 120 km (75 mi) segment of the Lenglongling Fault. A 23 km (14 mi) long[5] rupture occurred at the eastern end of the Huangcheng–Shuangta Fault with offsets of 0.1–2.8 m (3.9 in – 9 ft 2.2 in). Rupture on the Huangcheng–Shuangta Fault comprised reverse slip. The Southern Wuwei Basin Fault produced 42 km (26 mi) of vertical offsets in the range of 0.6–2.8 m (2 ft 0 in – 9 ft 2 in).[6]

See also

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References

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  1. ^ a b c d "NOAA page on the earthquake". Archived from the original on 14 August 2017. Retrieved 12 June 2010.
  2. ^ "Historic Earthquakes Tsinghai, China 1927 May 21 22:32 UTC". United States Geological Survey. Archived from the original on 21 June 2010. Retrieved 12 June 2010.
  3. ^ Gaudemer, Y.; Tapponnier P.; Meyer B.; Peltzer G.; Shunmin G.; Zhital C.; Huagung D. & Cifuentes I. (2007). "Partitioning of crustal slip between linked, active faults in the eastern Qilian Shan, and evidence for a major seismic gap, the 'Tianzhu gap', on the western Haiyuan Fault, Gansu (China)". Geophysical Journal International. 120 (3): 599–645. Bibcode:1995GeoJI.120..599G. doi:10.1111/j.1365-246X.1995.tb01842.x.
  4. ^ Cavalié, O.; Lasserre C.; Doin M.-P.; Peltzer G.; Sun J.; Xu X. & Shen Z.-K. (2008). "Measurement of interseismic strain across the Haiyuan fault (Gansu, China), by InSAR" (PDF). Earth and Planetary Science Letters. 275 (3–4): 246–257. Bibcode:2008E&PSL.275..246C. doi:10.1016/j.epsl.2008.07.057. Archived from the original (PDF) on 2011-07-21. Retrieved 12 June 2010.
  5. ^ Xu, X.; Yeats R.S. & Yu G. (2010). "Five Short Historical Earthquake Surface Ruptures near the Silk Road, Gansu Province, China". Bulletin of the Seismological Society of America. 100 (2): 541–561. Bibcode:2010BuSSA.100..541X. doi:10.1785/0120080282. Archived from the original on September 19, 2010. Retrieved 17 June 2010.
  6. ^ Guo, Peng; Han, Zhujun; Gao, Fan; Zhu, Chuanhua; Gai, Hailong (2020). "A New Tectonic Model for the 1927 M8.0 Gulang Earthquake on the NE Tibetan Plateau". Tectonics. 39 (9). Bibcode:2020Tecto..3906064G. doi:10.1029/2020TC006064.
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