Neotectonics, seismology and paleoseismology

Abstract

This chapter focuses on the neotectonics of Argentine–Chilean Patagonia and overviews the active tectonics of the southernmost region of South America, which constitutes a field of relatively recent development on a national standard. The presence of remarkable morphotectonic features associated with active faulting fronts in several of the defined seismotectonic regions indicates modern tectonic activity for this region of Patagonia. From the point of view of seismic risk studies, these regions have been subjected to various seismic effects and can be considered as units of potential risk. Once the different aspects of tectonics, large morphological features, seismic activity, and active volcanism have been analyzed individually, it is important to consider in combination because their occurrence indicates those regions where the earth's crust is being exposed to greater stresses and the resulting tension release. To properly estimate seismic risk in the Patagonian region, it is necessary to delimit these regions in such a way that they can be identified as independent units called “seismotectonic regions.” The four identified Patagonian seismotectonic regions are (1) Liquiñe–Ofqui–Fagnano, (2) Somuncurá (3) Agnia, and (4) Deseado.