Maochuan Zhang, University of Washington, School of Oceanography, Seattle, United States, William S D Wilcock, University of Washington Seattle Campus, School of Oceanography, Seattle, United States, Marine Denolle, University of Washington Seattle Campus, Department of Earth and Space Sciences, Seattle, United States, Felix Waldhauser, Columbia University, Lamont-Doherty Earth Observatory, Palisades, United States, Kaiwen Wang, Stanford University, Department of Geophysics, Stanford, United States, Maya Tolstoy, University of Washington, College of the Environment, Seattle, United States and Yen Joe Tan, The Chinese University of Hong Kong, Department of Earth and Environmental Sciences, Hong Kong, Hong Kong