Details
- Lecturer: Dr. Heinrich Brasse, Free University of Berlin
- Date: 27 March 2019; 12:00 h
- Place: Sala d’Actes de l’Institut de Ciències de la Terra Jaume Almera (ICTJA)
- Further information: Dr. Juanjo Ledo (UB)
Abstract
Magnetotelluric investigations in the South and Central American Subduction Zones revealed many electrical conductivity anomalies connected to widespread volcanism and magmatism. Smaller high-conductivity zones may reflect individual magma chambers beneath volcanic edifices at shallow depths (5-8 km), while large-scale anomalies in the mid crust (10-20 km depths) hint at a common magma source for a whole series of volcanoes. However, the by far largest conductive feature is the Altiplano-Puna Magma Body in the Bolivian backarc with a conductance of more than 20.000 Siemens which does not allow to resolve its lower limit. A critical assessment of 3-D inversion results and the influence of far-reaching crustal anisotropy will be discussed in this contribution.