Camilla Penney^1,2, Jean-Philippe Avouac² and Adriano Gualandi^3,4, (1)University of Cambridge, Cambridge, United Kingdom, (2)California Institute of Technology, Division of Geological and Planetary Sciences, Pasadena, CA, United States, (3)California Institute of Technology, Geological and Planetary Sciences, Pasadena, CA, United States, (4)NASA Jet Propulsion Laboratory, Pasadena, CA, United States