Assessment of paleoseismic heritage sites of Holocene megathrust earthquakes and tsunamis along the coast of south-centralChile (38°-42°S)

Earthquakes and tsunamis are natural phenomena that have strongly affected communities located along the Chilean active plate margin. Large-magnitude megathrust earthquakes produced at the plate interface of the subduction zone and their associated tsunamis have repeatedly impacted the Chilean coast, leaving a sedimentary record at particular sites from historic and prehistoric times. Here we assess paleoseismic sites related to late Holocene (< 1.5 ka) earthquakes and tsunamis that occurred along the Pacific coastline of south-central Chile (38°-42°S), which record critical information for the study of megathrust earthquakes. We focus on sites along the Valdivia segment that were affected by the great earthquake and tsunami of 1960 (Mw = 9.5; the largest recorded by modern seismology), which host geologic evidence of coseismic land-level changes found in tidal marshes and wetlands. We present an inventory of seven paleoseismic geosites composed mainly of different layers of buried soils and sand deposits, and a quantitative assessment of their scientific value, their potential touristic and educational value, and their degradation risk. These sites are considered part of the paleoseismic heritage of Chile and are relevant globally. Our inventory contributes to the establishment of management strategies for geoconservation of the coastal area of south-central Chile, and the mitigation of the effects of seismological hazards through the promotion of educational, touristic and outreach activities. [ABSTRACT FROM AUTHOR]