CONICET | Buscador de Institutos y Recursos Humanos

The earthquakeand tsunami of 1730 has been recognized as the largest to occur in MetropolitanChile since the beginning of written history. However, other giant earthquakesand tsunamis has been identief across the Andean subduction margin in recentcenturies (1868 and 1877 in the north of Chile, and 1960 in Valdivia). In mostcases, no predecessors to these events has been founded in the geological record.Furthermore, the recurrence interval and hazard posed by a future earthquake areunknown. Tree rings has been recognized worldwide as a powerful tool for datingvarious types of disturbance events (i.e oods, landslides and earthquakes) dueto its annual resolution, only a few studies have been carried out in Chilefocused on tectonic events. Our goal:Untangle the signature of mega earthquakescontain into the tree-ring width using a multi-species approach. We use threetree species distributed along South America in order to identi_ed signals ofmega earthquakes occurred during 1730, 1868, 1877 and 1960 year. To identifedthe signature of 1868 and 1877 events we used Polylepis tarapacana tree-ringwidth measurements, while to 1730 Austrocedrus chilensis rings have been used. Thesignature of 1960 were analyzed using tree-ring width of Pilgerodendronuviferum conifer. A battery of statistical (i.e. changepoint detection) andnumerical (i.e. heaviside) analyses were applied in order to identi_ed changesin tree-ring series during the event date. Most of 2000 tree-ring samples havebeen analyzed. Separate climate and tectonic signal contained into thetree-ring measurements. Understand the climatic-tectonic fedback captured bytree rings. Understand geomorphological features of each tree-ring sites atbasin and sub-basin scales.