Department Theoretical Geophysics, Utrecht University, Inst. Earth Science, Budapestlaan 4, Utrecht, 3508 TA Netherlands
Planetary sciences division, Caltech, MC-150-21, Pasadena, CA 91125, USA
Department Geology and Geophysics; University of Minnesota Supercomputer Institute, University of Minnesota, 108 Pillsbury Hall 310 Pillsbury Dr SE, Minneapolis, MN 55455-0219, USA