1946 Ancash earthquake
The 1946 Ancash earthquake in the Andes Mountains of central Peru occurred on November 10 at 17:43 UTC. The earthquake had a surface wave magnitude of 7.0, and achieved a maximum Mercalli intensity scale rating of XI ("Extreme"). About 1,400 Peruvians are thought to have died from the event. The quake was triggered by slippage along a normal fault at a depth of ~17.0 km with a magnitude of 6.9-7.3, as suggested by the focal mechanism. The fault was a shallow crustal structure on the South American Plate, as surface ruptures were observed with a maximum  offset of 3.5 meters. This event also reactivated several older thrust faults. These faults are part of the Marańón Thrust and Fold Belt, which formed in the Tertiary. The associated surface rupture of this quake ran for 21 km on the Quiches Fault; an active normal fault named after the town which suffered extensively during the quake. Many landslides were triggered by the very strong ground motions which was the reason for the high death toll and destruction. One of these slides completely buried the village of Acobamba in Suytucocha Valley.