1920 Hualien earthquake

Taiwan is located within a complex zone of convergence between the Philippine and Eurasian plates. Off the island's east coast, these plates converge at a rate of 75 mm per year. To the south of Taiwan, oceanic crust of the Eurasian plate is subducting beneath the Philippine Plate, creating an island arc, the Luzon Arc. At Taiwan the oceanic crust has all been subducted and the arc is colliding with continental crust of the Eurasian plate. To the north of Taiwan the Philippine Sea plate is in contrast subducting beneath the Eurasian plate, forming the Ryukyu Arc.{{Cite journal |last1=Molli G. |last2=Malavieille J. |title=Orogenic processes and the Corsica/Apennines geodynamic evolution: insights from Taiwan |journal=International Journal of Earth Sciences |date=2010 |volume=100 |issue=5 |pages=1207–1224 |doi=10.1007/s00531-010-0598-y|s2cid=129517282 }}

The earthquake had a moment-magnitude of 8.2 according to the International Seismological Centre. Lower-end estimates of the moment magnitude yielded a value of {{M|w}} 7.7 ± 0.2, which would still make it the largest in Taiwan. The USGS ShakeMap shows all areas of Taiwan felt shaking of between V and VII on the Modified Mercalli intensity scale. The shaking was also felt in southeast China, the island of Luzon in the Philippines, and southwest Japan.{{Cite web|title=M 8.2 – 47 km SE of Hualien City, Taiwan|url=https://earthquake.usgs.gov/earthquakes/eventpage/official19200605042135000_20/executive|publisher=United States Geological Survey}}

The source fault responsible for the earthquake has not been conclusively identified, although the epicenter location suggest it was associated with the southern portion of the Ryukyu subduction zone. Based on analyzing stations in Taiwan that recorded the earthquake, the hypocenter was determined to be within the accretionary wedge at {{cvt|20–35|km}} focal depth. The likely source is a rupture propagating down-dip and laterally along a splay fault associated with the subduction zone.{{cite journal |last1=Theunissen |first1=Thomas |last2=Font |first2=Yvonne |last3=Lallemand |first3=Serge |last4=Liang |first4=Wen-Tzong |title=The largest instrumentally recorded earthquake in Taiwan: revised location and magnitude, and tectonic significance of the 1920 event |journal=Geophysical Journal International |date=2010 |volume=183 |issue=3 |pages=1119–1133 |doi=10.1111/j.1365-246X.2010.04813.x|bibcode=2010GeoJI.183.1119T |doi-access=free }}

Eight deaths and 24 injuries were reported.{{Cite web|title=The 1920 Hualien Earthquake and Earthquake Risk in Taiwan|url=https://www.air-worldwide.com/blog/posts/2020/6/earthquake-risk-in-taiwan-100-years-after-hualien/|website=air-worldwide.com|date=4 June 2020|author=Stelios Minas}} 1,530 houses were affected in the cities of Taipei, Taitung, Hsinchu and Taoyuan, of which 273 were destroyed, and 277 others were severely damaged.{{Cite web|title=Event: Taiwan|url=https://www.ngdc.noaa.gov/hazel/view/hazards/earthquake/event-more-info/3154|publisher=National Geophysical Data Center}}

• List of earthquakes in Taiwan
• List of earthquakes in 1920
• 2018 Hualien earthquake
• 2019 Hualien earthquake

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{{Earthquakes in 1920}}

{{Earthquakes in Taiwan}}

Category:1920 earthquakes

Category:Earthquakes in Taiwan

Category:History of Hualien City

Category:Hualien County

Category:1920 in Taiwan