The 1868 Arica earthquake occurred on 13 August 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, Australia, 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 coasts of Peru and Chile have a history of great megathrust earthquakes originating from this plate boundary, such as the 1960 Valdivia earthquake and the 2010 Maule earthquake.