1. Department of Geological Sciences; University of Michigan; Ann Arbor Michigan USA
2. Department of Geology and Geochemistry; Stockholm University; Stockholm Sweden
3. Dipartimento di Scienze della Terra; Universita G. D'Annuzio, Campus Univeritario; Chieti Scalo Italy
4. Scripps Institution of Oceanography; University of California, San Diego; La Jolla California USA
5. Center for Geophysical Investigation for the Shallow Subsurface; Boise State University; Boise Idaho USA