Paleoseismic Evidence of an <i>M</i> _w 7 Pre‐Hispanic Earthquake in the Peruvian Forearc

We present the results of a paleoseismic survey Incapuquio Fault System, prominent transpressional fault system cutting forearc South Perú. High-resolution Digital Elevation Models, optical satellite imagery, radiocarbon dating, and trenching indicate that at least 2–3 m net slip occurred on generating complex, ∼100-km long set segmented scarps in early 15th century (∼1400–1440 CE). interpret consistent along-strike pattern scarp heights, geometries kinematics to reflect surface rupture generated by single Mw 7.4–7.7 earthquake, suggesting brittle failure poses significant, yet mostly overlooked, seismic hazard communities coastal areas The timing this earthquake coincides with collapse Chiribaya civilization ∼1360–1400 CE, we evidence damaged buildings along trace may be Chiribayas age. Our faulting observations, when combined observations deformation from geodesy seismology, also demonstrate Perú experiences time-varying permanent strain, for trench-parallel shortening, extension, trench-perpendicular shortening all close proximity but different periods megathrust cycle. recent are sense interseismic strain within measured GPS, is loaded toward between earthquakes.