1. Bigelow Laboratory for Ocean Sciences, West Boothbay Harbor, ME 04575.
2. Duke University Marine Laboratory, Beaufort, NC 28516.
3. National Bureau of Standards, Gaithersburg, MD 20899.
4. Institute of Marine Resources, Scripps Institution of Oceanography, La Jolla, CA 92093.
5. Center for Earth and Planetary Physics, Harvard University, Cambridge, MA 02138.
6. Instituto del Mar del Peru, Lima, Peru.