1868 Arica earthquake
|Date||August 13, 1868|
|Magnitude||8.5-9.0 Magnitude Mw|
|Countries or regions||Peru and parts of what is now northern Chile|
The 1868 Arica earthquake occurred on August 13, 1868, near Arica, then part of Peru, now part of Chile, at 21:30 UTC. It had an estimated magnitude between 8.5 and 9.0. A tsunami (or multiple tsunamis) in the Pacific Ocean was produced by the earthquake, which was recorded in Hawaii, Japan and New Zealand.
The earthquake occurred along the boundary between the Nazca Plate and the South American Plate. The earthquake was likely a result of thrust-faulting, caused by the subduction of the Nazca plate beneath the South American plate.
The tsunami drove three ships that had been anchored in the port nearly 800 m inland: the 1560-ton Peruvian corvette America, the U.S. gunboat Wateree and the U.S. store ship Fredonia, which was completely destroyed in the process. The English brig Chañarcillo and two Chilean schooners, Rosa Rivera and Regalon were also lost. The tsunami also caused the near complete destruction of the port city of Pisco.
The tsunami caused considerable damage in Hawaii, washing out a bridge along the Waiohi river. In New Zealand, substantial damage occurred on the Chatham Islands and the Banks peninsula with many houses washed away and boats damaged, but only one death was recorded.
The earthquake was felt over a very wide area, up to 1400 km to the northwest in Samanco, Peru and 224 km to the east in Bolivia. Estimates of its magnitude range from 8.5 to 9.0. A 600 km rupture length has been estimated from the pattern of isoseismals making it one of the largest fault breaks in modern times.
Although this event generated a tsunami that was noted across the Pacific, most of the associated damage was localised along the coasts of southern Peru and what is now northernmost Chile. The first wave arrived at Arica 52 minutes after the earthquake, with a 12 m height, followed by the largest 16 m wave 73 minutes later.
The Arica area forms part of a seismic gap between 15° and 24°S, with no major earthquake after 1877. In accordance with this theory "a strong event is likely to occur in the near future". An earthquake affecting the same sector of the plate boundary as the 1868 event with a magnitude of 8.6 has been forecast as likely to occur by 2010. A repeat of the 1868 event would probably cause more casualties, because of the increase of population in areas at risk.
- IISEE. "Catalog of Damaging Earthquakes in the World (Through 2007)". Archived from the original on 6 March 2010. Retrieved 2010-02-28.
- USGS (26 October 2009). "Arica, Peru (now Chile) 1868 August 13 21:30 UTC". Historic Earthquakes. Archived from the original on 16 January 2010. Retrieved 28 February 2010.
- Rabinovich, A.B.; Kulikov E.A. & Thomson R.E. (2001). "Tsunami risk estimation for the coasts of Peru and northern Chile". ITS 2001 Proceedings, Session 1. pp. 281–291. Retrieved 28 February 2010.
- Zamudio, Y.; Berrocal J. & Fernandes C. (2005). "Seismic hazard assessment in the Peru-Chile border region". 6th International Symposium on Andean Geodynamics. pp. 813–816. Retrieved 28 February 2010.
- Allen, G.W. (April 1869). The Great South American Earthquakes of 1868. Harper's New Monthly Magazine. p. 613. Retrieved 6 December 2010.
- Okal, E.A.; Borrero J.C. & Synolakis C.E. (2006). "Evaluation of Tsunami Risk from Regional Earthquakes at Pisco, Peru". Bulletin of the Seismological Society of America 96 (5): 1634–1648. Bibcode:2006BuSSA..96.1634O. doi:10.1785/0120050158. Retrieved 2010-03-01.
- NGDC. "Page on 1868 event". Retrieved 28 February 2010.
- Canque, Manuel Fernández (January 2007). Arica 1868: Un Tsunami y Un Terremoto. University of Tarapacá. ISBN 978-9562441940.
- Media related to 1868 Arica earthquake at Wikimedia Commons