JAMSTEC, Japan Marine Science & Technology Center, Deep Sea Research Dept., 2-15 Natsushima-cho, Yokosuka-shi, Kanagawa 237-0061, Japan Now at WHOI, Geology & Geophysics Department, 360 Woods Hole Rd., Woods Hole, MA 02543-1542 United States
Univ. Ryukyus, Department of Physics & Earth Sciences, Senbaru-1, Nishihara, Okinawa, 903-0213 Japan
Dynamics of Lithosphere Lab, CC.60, place Bataillon, Montpellier, 34095 France