August 13, 1868 Tsunami: Northern Chile

Reference #415:

1868, August 13, 21:30 UTC. Two great earthquakes at Arica, Peru (now Chile) on Aug 13 21:30 UTC and Aug 14 01:30 UTC with magnitudes up to 8.5, generated catastrophic tsunamis that affected the entire Pacific rim and lasted 2-3 days. 21 m waves were generated locally. In South America, more than 25,000 people were killed from the earthquake and tsunami and several settlements along the Peru-Chile coast were destroyed.

The tsunami which followed the earthquake affected the coast of Peru and Chile, at least from Trujillo (where there was damage) to Chiloe Island. The belt most affected by the tsunami extended approximately from Chala and Islai to Iquique; it is possible that the mean rise of water exceeded 10 m here. The oscillations in level apparently began with the flood tide, but at most places, especially those remote from the source, the subsequent stronger ebb was noticed first. The tsunami did the greatest material damage at Arica.

The Arica tsunami affected practically the entire Pacific rim and lasted at least 2-3 days. It was registered by six tide gauges: at Sydney, on Kodiak Island, at Astoria, San Francisco, Los Angeles and San Diego. However, one cannot confidently pin-point the onset of the tsunami even on the tide gauge records, and for this reason, the published data on the travel time of the tsunami are unreliable.

NOTE: All of the associated runup locations are listed with the first event. The earthquake was accompanied by an enormous number of recurrent shocks.

Waves from the first event (Aug 13 21:30 UTC) arrived at the Hawaiian Islands about 1:00 a.m. local time and from the second at 5:00 a.m. Aug 14.

Waves from the first event (Aug 13 21:30 UTC) arrived at San Diego about 2:00 a.m. local time Aug 14. The maximum recorded amplitude was 1.3 feet at San Diego and 0.9 feet at Fort Point, San Francisco.

Waves from the second event (Aug 14 01:30 UTC) arrived at Kodiak, Alaska, between 10 a.m. and 2 p.m. local time Aug 14 and at Astoria, Oregon at about 8 a.m. local time Aug 14. (Ref #239)

Reference #415 lists 15-18 m waves at Arica, Chile.

August 12 (or 11), 1868, 4:00 [local time]. An earthquake was felt at Acapulco (although not by all residents). A weaker shock was noticed at 11:00. Apparently, the unusual flood and ebb tides of the sea, observed from morning until 20:00, should be ascribed to this earthquake. The water at first retreated 35 m (40 vara) beyond its usual mark, and then covered the shore also for 35 m (40 vara) beyond the usual line, flooding nearby homes. [Probably effects of the Arica, Peru tsunami, August 13, 1868].

Reference #10885:

More than 30 thousand people perished and the material and financial losses were incalculable.