PALEOSEISMOLOGY IN COASTAL CHILE

The fossil shorelines of the Chilean coast reflect interseismic as wel l as coseismic movements, The earthquake record is further obscured by the variable pattern of coastal deformation that accompanies large ea rthquakes, such as the longitudinal warping associated with the 1960 V aldivia (M(w)=9.5) earthquake. The number of events recorded is a mini mum, as relaxation can lead to the reoccupation of shorelines, and pal eoearthquake magnitude cannot be determined with confidence, as the am ount of uplift or subsidence depends on location within the deformed z one and on the timing of the measurements during the deformation cycle . However, provided radiometric dating makes it possible to discrimina te between successive earthquakes, variations in the amount of uplift can be used for modeling the deformation numerically to the ultimate b enefit of seismic hazard assessment.