November 1960 Peru earthquake

The November 1960 Peru earthquake occurred offshore northern Peru on November 20 at 17:02 local time. The magnitude of the earthquake was put at M_s 6.75 by using the conventional magnitude measurement within a shorter duration of ~20 s. However, there is a large discrepancy between the magnitudes in M_s and M_w in this earthquake. The discrepancy was resulted from that the earthquake had a long source duration of about 130 s, and by calculating the seismic moment, the magnitude would be M_w 7.6 or M_w 7.8, according to different sources. This earthquake belongs to a category of earthquakes with slow rupture velocities and potential of producing tsunamis larger than those expected from the moment magnitudes.

This earthquake triggered a tsunami with a height of 9 meters (30 ft) in Puerto Eten, Lambayeque Department. The tsunami caused damage along the coast of the Lambayeque department. Three deaths were reported in Lambayeque Department. Thirteen deaths and 50 missing were reported in Guañape Islands, La Libertad Department. The tsunami was also observed in Japan.