The 1960 Valdivia earthquake's rupture lasted about 10 minutes. It struck southern Chile on May 22, 1960, and is generally regarded as the strongest earthquake ever recorded instrumentally, with an estimated magnitude of 9.4–9.6.
The event was a massive megathrust earthquake on the boundary where the Nazca Plate dives beneath the South American Plate. Its rupture propagated along roughly 1,000 kilometers of Chile's coastline, producing exceptionally long and powerful shaking. The duration refers to the main rupture and intense earthquake motion, not to the entire sequence of foreshocks and aftershocks.
The earthquake also generated a Pacific-wide tsunami. Waves devastated coastal Chile and traveled across the ocean to Hawaii, Japan, the Philippines, New Zealand, and other locations. In some places, tsunami damage occurred many hours after the shaking had ended.
A common mix-up is confusing the earthquake's 10-minute duration with the timing of later tsunami waves or with the wider series of Chilean earthquakes that occurred before and after the main shock.