Fidel COSTA, a Principal Investigator with the Volcano group at EOS, is an igneous petrologist and geochemist specializing in volcanic processes. His main research interests are the conditions (pressure, temperature, volatile contents) and processes that magmas experience below active volcanoes and how these relate to volcanic unrest phenomena. He studied Earth Sciences at the University of Barcelona (Spain), and received his Ph.D. from the University of Geneva (Switzerland). He was Marie Curie Fellow (CNRS, Orleans), and subsequently held positions as a Post-Doctoral Fellow at Ruhr-University, Bochum (Germany), and at the CSIC in Barcelona (Ramon y Cajal Fellow). He has been involved in developing new geochronological methods to determine the rates of volcanic and magmatic processes occurring on human time scales.