John P Platt¹, Thomas M Mitchell², David John Prior³, Marianne Negrini³, Sheng Fan³, Mark Jefferd⁴ and Blaise Robertson Winnard⁴, (1)University of Southern California, Earth Sciences, Los Angeles, CA, United States, (2)University College London, Department of Earth Sciences, London, United Kingdom, (3)University of Otago, Dunedin, New Zealand, (4)University College London, Rock and Ice Physics and Seismological Laboratory, London, United Kingdom