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The 1960 Valdivia earthquake and tsunami (Spanish: Terremoto de Valdivia) or the Great Chilean earthquake (Gran terremoto de Chile) occurred on 22 May 1960.

Most studies have placed it at 9.4–9.6 on the moment magnitude scale, making it the strongest earthquake ever recorded, while some studies have placed the magnitude lower than 9.4. The resulting tsunamis affected southern Chile, Hawaii, Japan, the Philippines, eastern New Zealand, southeast Australia, and the Aleutian Islands. The epicenter of this megathrust earthquake was near Lumaco, approximately 570 kilometres (350 mi) south of Santiago, with Valdivia being the most affected city. The tremor caused localized tsunamis that severely battered the Chilean coast, with waves up to 25 metres (82 ft). The main tsunami traveled across the Pacific Ocean and devastated Hilo, Hawaii, where waves as high as 10.7 metres (35 ft) were recorded over 10,000 kilometres (6,200 mi) from the epicenter. Various estimates of the total number of fatalities from the earthquake and tsunamis have surfaced, ranging between 1,000 and 6,000 killed. Different sources have estimated the monetary cost ranged from US$400 million to $800 million (or US$4.4 billion to $8.7 billion in 2025, adjusted for inflation).

The earthquake was a megathrust earthquake resulting from the release of mechanical stress between the subducting Nazca plate and South American plate on the Peru–Chile Trench, off the coast of southern Chile.

The focus of the earthquake was relatively shallow at 33 km (21 mi), considering that earthquakes in northern Chile and Argentina may reach depths of 70 km (43 mi). In other words, the previous and current more widely accepted explanation for the earthquake involves the Peru-Chile Trench slipping further than its accumulated slip deficit (the amount of slip available for an earthquake) should allow. While the Valdivia earthquake was extraordinarily large, the 2016 Chiloé earthquake hints that it did not release all the potential slip in that segment of the plate interface.

The 1960 Chilean earthquakes were a sequence of strong earthquakes that affected Chile between 21 May and 6 June 1960, centered in the Cautín, Malleco, Aysén, and Biobío provinces of the country. The first of these was the 8.1 Mw Concepción earthquake at 06:02 UTC-4 on 21 May 1960.

The Valdivia earthquake occurred at 15:11 UTC-4 on 22 May, and affected all of Chile between Talca and Chiloé Island, more than 400,000 square kilometres (150,000 sq mi). The two most affected areas were Valdivia and Puerto Octay, near the northwest corner of Llanquihue Lake.

This magnitude 7.7 earthquake probably occurred along the Liquiñe-Ofqui Fault, meaning that the fault would have moved as a consequence of the 22 May Valdivia earthquake.

In the Valdivia River and Corral Bay, several vessels were wrecked by the earthquake, among them Argentina, Canelo, Carlos Haverbeck, Melita, and the salvaged remnants of Penco. After hours of drifting around in Corral Bay and Valdivia River, the ship was wrecked and subsequently abandoned by its crew at 1800 local time.

On 24 May, 38 hours after the main shock of the 1960 Valdivia earthquake, the Cordón Caulle volcano erupted.

Before the earthquake, some of these blocks had modern concrete buildings built after the Great Valdivia fire of 1909.

2 m of subsidence caused by the earthquake.

There is evidence that a similar earthquake and landslide occurred in 1575 in Valdivia. While the 1575 earthquake is considered the one most similar to that of 1960, it differed in not having caused any tsunami in Japan. On 27 February 2010 at 03:34 local time, an 8.8 magnitude earthquake occurred just to the north (off the coast of the Maule region of Chile, between Concepción and Santiago). This 2010 earthquake was the largest to affect Valdivia since the 1960 event. Some sidewalks near the river shore in Valdivia cracked and collapsed much like in the 1960 earthquake.

Quick Facts

• The epicenter of this megathrust earthquake was near Lumaco, approximately 570 kilometres (350 mi) south of Santiago, with Valdivia being the most affected city.
• The earthquake was a megathrust earthquake resulting from the release of mechanical stress between the subducting Nazca plate and South American plate on the Peru–Chile Trench, off the coast of southern Chile.
• This magnitude 7.7 earthquake probably occurred along the Liquiñe-Ofqui Fault, meaning that the fault would have moved as a consequence of the 22 May Valdivia earthquake.
• The Valdivia earthquake occurred at 15:11 UTC-4 on 22 May, and affected all of Chile between Talca and Chiloé Island, more than 400,000 square kilometres (150,000 sq mi).
• On 24 May, 38 hours after the main shock of the 1960 Valdivia earthquake, the Cordón Caulle volcano erupted.

Source material: Wikipedia - "1960 Valdivia earthquake". Adapted and summarized for DiscoverScroll. Original contributors are credited through the linked Wikipedia article. Read original on Wikipedia. CC BY-SA 4.0. Changes were made from the original.