Kurt L Feigl, University of Wisconsin Madison, Geoscience, Madison, WI, United States, Hélène Le Mével, Carnegie Institution for Science, Department of Terrestrial Magnetism, Washington, DC, United States, Loreto Córdova, Observatorio Volcanológico de los Andes del Sur (OVDAS), Servicio Nacional de Geología y Minería (SERNAGEOMIN), Temuco, Chile, David P Bekaert, NASA Jet Propulsion Laboratory, Pasadena, United States and Bradley S Singer, University of Wisconsin Madison, Madison, WI, United States