Chile has had three tsunamis since 1868, all occurring after major earthquakes. On the 13th of August, 1868 a 9.0-magnitude earthquake struck, offshore, between the borders of Peru and Chile creating a massive tsunami. It was 4:45 in the afternoon and the first tsunami made land shortly thereafter, with two-more consecutive waves hitting the coast over a period of forty minutes. The largest wave would hit some 4-hours after the quake. This same tsunami would devastate Hawaii, New Zealand, Chatham Island, and most of the Pacific Basin. The combined earthquake and tsunami death toll was 25-thousand persons.
On the 22nd of May, 1960 the largest earthquake ever recorded occurred in the Valdivia-Puerto Montt area of Chile. The 9.6-magnitude earthquake caused a tsunami, hitting Chile initially, and spreading outward across the Pacific Ocean. It would make land at Hilo within 15-hours. Seven hours later, the wave would flood Japan, and cause damage in portions of Samoa and New Zealand. Once again, the combined disaster killed 1886-people with some 3000 injured and missing. Damages were estimated at a combined total of $580-million and left well-over 200-million homeless. The largest waves were 38-feet in height, and it was one of these that completely destroyed Puerto Saavedra on the Chilean Coast. There were subsequent landslides in Chile that further devastated the country. Hilo, in the Hawaiian Island chain, was hit the hardest of the Pacific Basin region.
There had been 4-foreshocks of 7.0 magnitude with the largest of 7.9-magnitude on the 21st of May, and then on the 24th of May, Puyehue Volcano erupted. This same volcano, having lain dormant since 1960, erupted in June of this year spewing ash 6-miles into the atmosphere.
The most recent earthquake-tsunami combination to hit Chile was in February of 2010. The quake was of 8.8-magnitude, and was located at a depth of 21.7-miles beneath the crust. This latest quake occurred just a few miles north of the 1960s epicenter. It was 700 to 800-times stronger than the earthquake that hit Haiti but its depth kept it from causing as much destruction and death. According to the U. S. Geological Survey, Chile has had 13-earthquakes of magnitude 7.0 or greater since 1973.
The Nazca Plate and the South American Plate form a subduction zone, which are potential locations for tsunamis. The cause of these tsunamis was a result of the Nazca Plate slipping beneath the South American Plate, which caused the land to sink and the ocean floor to rise.