Seismological Studies of the Central and Southern Andes

Abstract

The central Andes have formed by the complex interaction of subduction-related and tectonic processes on a lithospheric scale.The deep structure of the entire mountain range and underlying subduction zone has been investigated by passive and activeseismological experiments. Detailed tomographic features are interpreted to represent the ascent paths of fluid and meltsin the subduction zone and provide new insights about the mechanisms of lithospheric deformation. Receiver functions fromteleseismic events have been used to observe the upper-plate continental Moho and subducted oceanic Moho, as well as the interactionof subducted oceanic lithosphere and mantle discontinuities. A second working area was established in the southern Andes tocompare two different types of Andean subduction and to identify the principal controlling parameters. Besides the first accuratedefinition of the Wadati-Benioff zone in south-central Chile, a three-dimensional, tomographic velocity model based on localearthquakes in the southern Andes is presented.