Historic Earthquakes

Arica, Peru (now Chile)
1868 August 13 21:30 UTC
Magnitude 9.0

Two great earthquakes occurred at Arica, Peru (now Chile) that generated catastrophic tsunamis that affected locations throughout the Pacific Basin. The towns of Arica, Arequipa, Moquegua, Mollendo, and Ilo were largely destroyed by the earthquake. In South America, more than 25,000 people were killed from the earthquake and tsunami.

From the National Geophysical Data Center (NGDC) Significant Earthquake Database.

1868. 13 August, at 16:45 (local time). Intensity XI earthquake accompanied by a tsunami. The historian Dr. J. Y. Polo refers to this shock as one of the strongest that has been verified in Peru since the Conquest. Macroseismic observations indicate that the center of the earthquake was in the port of Arica. Along the coast it caused much havoc, being felt some 1400 km to the northwest (Samanco, Peru) and at an equal distance to the south (Valdivia, Chile). In Bolivia it was felt 224 km away east of La Paz, in the direction of Cochabamba. In Arequipa, according to witnesses, "the ground creaked and undulated, it being hard to remain standing. Walls fell, and broke into large sections." The radius of the pleistoseismal area was some 700 km2. Within this area there was heavy destruction at Arica, Tacna, Moquegua, Ilo, Torata, and Iquique; the city of Arequipa was in ruins. At Moquegua 150 people died, in Arequipa 10, and Tacna 3. At 17:37 there began am impetuous overflow of the sea. The first wave reached a height of twelve meters, and completely eradicated the harbor of Arica, carrying away on its backwash everything it met in its path. The flux and reflux lasted some 40 minutes. There was a series of strong currents. At 18:50 the sea again invaded with waves 16 meters high. The waters turned and receded. The third wave invaded the land again at 19:10. This last wave stranded the 1560-ton Peruvian corvette "America", the "Wateree" of the United States, and the lighter "Fredonia", which were carried 300 meters inland. The backwash of the sea razed a large part of the Peruvian coast, killing 30 people at Chala, about 100 at Arica, and 200 at Iquique. The agitation of the ocean reached as far as California, Hawaii, Yokohama, the Philippines, Sydney, and New Zealand. It is reported that the earth opened up in various places, spewing out muddy water. The Headland at Arica was fractured, likewise the hills of La Caldera, next to the baths of Yura (Arequipa). About 400 movements or aftershocks were counted up to the 25th of August.

Abridged from Historia de los sismos mas notables ocurridos en el Perú (1513-1970): Geofísica Panamericana, v. 2, no. 1, January 1973, Enrique Silgado F.