1. Woods Hole Oceanographic Institution
Woods Hole, MA 02543, USA
pclift@whoi.edu
2. Institute of Earth Sciences, Free University Amsterdam
de Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
3. Bundesanstalt für Geowissenschaften und Rohstoffe (BGR)
Stilleweg 2, D-30655 Hannover, Germany
4. Lasmo plc
101 Bishops Gate, London EC2M 3XH, UK