1. U.S. Geological Survey Pasadena, California 91106
2. I.G.P.P. Scripps Institution of Oceanography UCSD, La Jolla, California 92093
3. Department of Earth and Space Sciences UCLA Los Angeles, California 90024
4. Department of Geological Sciences Stanford University Stanford, California 94305
5. U.S. Geological Survey Menlo Park, California 94025
6. Lawrence Livermore National Lab Livermore, California 94550