Of the world's 36 known earthquakes with M ≥ 8.5 since the year 1500, one-third occurred in Chile and are shown in the map to the side. Some virtually have the same epicenters like the 1604 and 1868 (in Arica), the 1730 and 1822 (in Valparaíso), the 1751 and 1835 (in Concepción), and the 1575 and 1837 (in Valdivia).