Department of Earth Sciences, University of Southern California, Zumberge Hall of Science 3651 Trousdale Pkwy, Los Angeles, CA 90089-0740 United States
Institute for Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093-0225 United States
CIRES, University of Colorado Boulder, Department of Geological Sciences 399, Boulder, CO 80309-0399 United States