1. 1Department of Earth Sciences and Southern California Earthquake Center, University of Southern California, Los Angeles, California, U.S.A.
2. 2Department of Geophysics, Stanford University, Palo Alto, California, U.S.A.
3. 3Helmholtz Centre Potsdam German Research Centre for Geosciences GFZ, Potsdam, Germany
4. 4Department of Earth Sciences, Free University Berlin, Berlin, Germany
5. 5Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, U.S.A.
6. 6Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität München, Munich, Germany
7. 7Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia