Valdivia Earthquake – 1960

The world’s most powerful earthquake – impressively titled Gran terremoto de Valdivia in Spanish – rocked Chile in May 1960.

It measured an unprecedented 9.5 on the moment magnitude scale (MMS), regarded by seismologists as the most accurate measure of energy released by a quake. The epicenter of the Valdivia earthquake was near Canete, 900 km (435 mi) south of the capital, Santiago, but was named after the city that took the biggest hit.

There had already been a smaller earthquake that cut off communications to Southern Chile on May 21 and rescue efforts were underway when the big one struck on the following day, with terrible consequences. Two fifths of Valdivia’s buildings were razed to the ground and many more were damaged, including much of the city’s industrial capacity. Power and water supplies were knocked out, hundreds died and people were made homeless. A landslide blocked the outflow of nearby Rinihue Lake, creating a dam that threatened to burst and unleash a devastating flash flood – a danger averted by feverish work to lower the dam and release water in a controlled manner. Beyond Valdivia, a vast tract of Chile was seriously affected as coastal settlements were wiped out by tsunamis, ships sank and extensive flooding was experienced.

Damage caused by this awesome natural phenomenon wasn’t confined to Chile, as a tsunami raced across the Pacific Ocean with 10 m (35 ft) waves recorded 10,000 km (6,000 mi) from the epicenter, as far away as the Philippines and Japan. The impact was particularly severe in Hawaii, where the coastal town of Hilo was devastated and 61 people died. Valdivia itself never really recovered Already subject to economic decline, in 1974 it lost regional capital status to Puerto Montt. Many sites in Valdivia where the quake destroyed buildings have never been redeveloped.

When: May 22 1960

Where: Southern Chile

Death toll: Estimates of the number of casualties directly attributable to the Valdivia earthquake (sometimes called the Great Chilean Earthquake) vary considerably, from around 2,000 to over 6,000.

You should know: Two members of the indigenous Mapuche community from Chile’s Araucania region made a human sacrifice in an attempt to placate angry gods that had sent earthquake and flood. A five-year-old boy had his arms and legs cut off, with the severed limbs being stuck into the beach like talismanic posts to be carried away by the tide. TWO men were convicted of the sacrifice but released when a judge ruled they had been compelled to act by the irresistible force of ancestral tradition.