The earthquake had a surface-wave magnitude of 7.0,[2] and achieved a maximum Mercalli intensity scale rating of XI (Extreme).

Despite being located in a zone of compression, shallow continental extension occur beneath the Andes mountains, within the overriding South American plate.

[4] The earthquake was triggered by slippage along a shallow-angle normal fault at a depth of ~17 km (11 mi), as suggested by the focal mechanism.

[1] The fault was a shallow crustal structure on the South American plate, as surface ruptures were observed with a maximum offset of 3.5 m (11 ft).

[7] Shallow intraplate earthquakes within the South American plate are rare due to the long recurrence intervals on faults.

[8] Shaking was felt over a 600,000 km2 (230,000 sq mi) area, being most severe in the departments of Ancash and La Libertad.

The maximum Modified Mercalli intensity, X–XI, was felt in a thin strip of area from Cerro Pelagatos to the villages of Mayas and Quiches.