1. Geosciences Research DivisionScripps Institution of Oceanography, University of California San DiegoLa Jolla CA USA
2. Department of Earth, Ocean and Atmospheric SciencesUniversity of British ColumbiaVancouver BC Canada
3. Planetary Science InstituteTucson AZ USA
4. Institute of Geophysics and Planetary Physics, Scripps Institution of OceanographyUniversity of California San DiegoLa Jolla CA USA