1. Departamento de Geociencias, Universidad de Los Andes, Bogotá, Colombia
2. School of Physics and Astronomy and Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom
3. Departamento de Física, Universidad de Los Andes, Bogotá, Colombia
4. Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA