1. Federal Institute for Geosciences and Natural Resources; D-30655; Hannover; Germany
2. GNS Science; 1 Fairway Drive, Avalon,; P.O. Box 30 368,; Lower Hutt; New Zealand
3. Geotech Ltd.; Aurora, Ontario; L4G 4C4; Canada
4. Marine Physics Branch; Naval Research Laboratory; Code 7420, 4555 Overlook Avenue SW,; Washington, D. C.; 20375; USA
5. National Geodetic Survey; NOAA; 1315 East-West Highway, SSMC-3,; Silver Spring; Maryland; 20910; USA
6. Geological Survey of Canada; 615 Booth Street,; Ottawa, Ontario; K1A 0E9; Canada
7. U.S. Geological Survey; Denver Federal Center; P.O. Box 25046, MS 964,; Denver; Colorado; 80225; USA
8. School of Earth Sciences; Ohio State University; Columbus; Ohio; 43210; USA
9. Geological Survey of Norway; Leiv Eirikssonsvei 39,; Trondheim; N-7491; Norway
10. All-Russian Research Institute for Geology and Mineral Resources of the World Ocean; 1 Angliysky Avenue,; Saint Petersburg; 190121; Russia
11. Helmholtz Centre Potsdam; German Research Centre for Geosciences; D-14473; Potsdam; Germany
12. Geoscience Australia; Canberra; ACT 2601; Australia
13. College of Sciences; King Saud University; Riyadh; 11451; Saudi Arabia
14. School of Geosciences; University of Sydney; Sydney, New South Wales; 2006; Australia
15. Institut de Physique du Globe de Paris; 4 place Jussieu,; F-75252; Paris; France
16. Istituto Nazionale di Geofisica e Vulcanologia; via Pezzino Basso, 2,; I-19020; Fezzano; Italy