1. W. S. Holbrook, H. Hoskins, R. A. Stephen, Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
2. W. T. Wood, Naval Research Laboratory, Stennis Space Center, MS 39529, USA.
3. D. Lizarralde, Massachusetts Institute of Technology-Woods Hole Joint Program, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.