The 1985 Pichilemu earthquake occurred on 8 April at 21:56:59 local time with a moment magnitude of 7.5 and a maximum perceived intensity of VII (Very Strong). The shock was centered 75 kilometres (47 mi) southwest of Santiago, Chile, with a focal depth of 37.8 km (23 mi).
Although it has been considered by the news media as an aftershock of the main Santiago earthquake, according to Rosa Urrutia de Hazbún and Carlos Lanza Lazcano's book Catástrofes en Chile 1541–1992, the Pichilemu earthquake was a different and separate event.
A magnitude 8.0 earthquake was registered on 3 March 1985 offshore Valparaíso, Valparaíso Region. It reached a maximum intensity of XI on the Mercalli intensity scale. 177 people were killed, 2,575 injured, 142,489 houses were damaged and about a million people were left homeless. There was a long interruption on basic services, and the damage provoked by that earthquake was estimated to be more than 1,046 million US dollars.