The 1985 Rapel Lake earthquake[4][5] occurred on 8 April at 21:56:59 local time with a moment magnitude of 7.2 and a maximum perceived intensity of VI (Strong).

[8] The earthquake, measured in the Modified Mercalli intensity, reached magnitude VI in Curacaví, La Calera, Los Andes, Peñaflor, San Antonio, Valparaíso, and Viña del Mar; and magnitude V–VI in Concón, Constitución, Curicó, La Ligua, Melipilla, Papudo, Pichilemu, Puchuncaví, Quilpué, and Villa Alemana.

[2] According to national radio networks, the tremors "were felt along a 1,000-mile stretch of Chile from Copiapó in the north to Valdivia in the south and across the Andes mountains in Argentina".

[10] Mario Pardo, the director of the Chilean Seismological Service, told international press in April 1985 that it was "apparently an aftershock from the 3 March earthquake that killed 177 in central Chile" and that "the quake was centered in the ocean off the coast near Pichilemu, a city 100 miles southwest of Santiago".

[9] According to national radio networks, the tremors "were felt along a 1,000-mile stretch of Chile from Copiapó in the north to Valdivia in the south and across the Andes Mountaines in Argentina".