1. Department of Terrestrial Magnetism Carnegie Institution for Science Washington DC USA
2. Department of Geosciences The Pennsylvania State University University Park PA USA
3. Department of Space, Earth and Environment Chalmers University of Technology Gothenburg Sweden
4. Observatorio Vulcanológico y Sismológico de Costa Rica Universidad Nacional de Costa Rica Heredia Costa Rica
5. School of Earth and Environmental Sciences The University of Manchester Manchester UK
6. Instituto Nicaragüense de Estudios Territoriales Managua Nicaragua