M 7.1 - 16 km WSW of Atiquipa, Peru

Tectonic Summary

The Peru earthquake of September 25, 2013, occurred as the result of shallow thrust faulting on or near the boundary between the South America plate and the subducting Nazca plate.  The Nazca plate subducts beneath the South America plate at the Peru-Chile Trench offshore of western South America, and the thrust interface between the two plates dips east-northeast beneath the South American continent. At the location of the earthquake, the Nazca plate moves to the east-northeast with respect to the South America plate at a velocity of about 70 mm/yr. 

The boundary region between the Nazca and South America plates experiences a large number of earthquakes. The region within 250 km of the epicenter of the earthquake of September 25 has experienced 17 previous earthquakes of M 6+ since 1973. The largest of these, the M 8.4 earthquake of June 23, 2001, occurred along the plate boundary to the south.  It resulted in at least 74 fatalities and destroyed more than 17,000 homes. The M 7.7 earthquake of November 12, 1996, resulted in at least 14 fatalities and left 12,000 people homeless. It occurred along the plate boundary to the north of the September 25th epicenter.

Hayes et al. (2016) Tectonic summaries of magnitude 7 and greater earthquakes from 2000 to 2015, USGS Open-File Report 2016-1192. (5.2 MB PDF)