1. Instituto Technológico y de Energías Renovables (ITER), 38900 Granadilla de Abona, Tenerife, Canary Islands, Spain
2. Instituto Volcanológico de Canaries (INVOLCAN), 38400 Puerto de la Cruz, Tenerife, Canary Islands, Spain
3. School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, U.K.
4. Research Complex at Harwell, Rutherford Appleton Laboratories, Didcot, OX11 0FA, U.K.
5. Diamond Light Source Ltd., Didcot, OX11 0DE, U.K.
6. FEI, Stiklestadveien 1, 7041 Trondheim, Norway
7. Geological Survey of Finland, Fl-02151 Espoo, Finland
8. Institute of Earth Sciences, University of Iceland, Reykjavik 101, Iceland
9. Scientific Computing Department, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Campus, OX11 0QX, U.K.
10. Leeds Electron Microscopy and Spectroscopy Centre, University of Leeds, Leeds, LS2 9JT, U.K.
11. Mechanical Engineering, University College London, Gower Street, London, WC1E 6BT, U.K.