M 9.5 Earthquake - May 1960, Chile

On 22 May 1960 a massive earthquake with a moment magnitude of 9.5 struck 10 km offshore of southern Chile at a depth of 33 km¹. During the earthquake, the South American Plate lurched by as much as 18.2 m relative to the subducting Nazca plate across an area 966 km long and 161 km wide². The earthquake released 250-350 years worth of plate motion in the area³. The earthquake also triggered a devastating tsunami.

¹ Roeloffs, E.A. 2006. Evidence for aseismic deformation rate changes prior to earthquakes. Annual Review of Earth and Planetary Sciences. Vol. 34, pp 591-627

² Atwater, B.F, Cisternas, M, V, Bourgeois, J, Dudley, W.C, Hendley II, J.W & Stauffer, P.H. 1999. Surviving a tsunami - Lessons from Chile, Hawaii and Japan. US Geological Survey Circular 1187

³ Cisternas, M, Atwater, B.F, Torrejn, F, Sawai, Y, Machuca, G, Lagos, M, Eipert, A, Youlton, C, Salgado, I Kamataki, T, Shishikura, M, Rajendran , C.P, Malik9, J.K, Rizal , Y & Husni , M. 2005. Predecessors of the giant 1960 Chile earthquake. Nature, Vol. 437, pp 404-407