Which earthquake produced the 1960 Valdivia tsunami in Chile?

The earthquake that produced the 1960 Valdivia tsunami in Chile was the 1960 Valdivia earthquake.

It struck southern Chile on 22 May 1960 and is commonly estimated at magnitude 9.5. It remains the largest earthquake recorded by modern instruments. The rupture occurred along the subduction boundary where the Nazca Plate moves beneath the South American Plate.

The earthquake generated a powerful tsunami that crossed the Pacific Ocean. Waves struck Chile, Hawaii, Japan, the Philippines and other coastlines, causing deaths and damage thousands of kilometres from the rupture. Local landslides and ground failure added to the destruction in Chile.

The event is sometimes called the Great Chilean earthquake. It should not be confused with the 2010 Maule earthquake, another major Chilean subduction earthquake that occurred farther north.