Dr. John Weeks, Ph.D., Stanford University
        at Brown !980-1994.

Dr. Shuqing Zhang, Ph.D., Australian National University
        at Brown June 1995-Nov. 1996.

Dr. David Goldsby, PH.D., Univ. Minnesota
        at Brown January, 1997-present

Dr. Stephane Bouissou, Université Montpellier, France
        at Brown, January 1999-August 1999

Dr. Naoyuki Kato, Geological Survey of Japan
        at Brown, March 1999-March 2001