Marleen Carolijn de Ruiter, Vrije Universiteit Amsterdam, Amsterdam, Netherlands, Anais Couasnon, Vrije Universiteit Amsterdam, Institute for Environmental Studies (IVM), Amsterdam, Netherlands, Marc van den Homberg, Red Cross 510 Global Office, Data Team, 's Gravenhage, Netherlands, James E Daniell, Karlsruhe Institute of Technology, Geophysical Institute, Karlsruhe, Germany, Joel Gill, British Geological Survey, Global, Nottinghamshire, United Kingdom and Philip Ward, IVM - VU University Amsterdam, Amsterdam, Netherlands