1. Department of Earth Sciences; University of New Hampshire; Durham New Hampshire USA
2. Now at Institute for Geophysics, Jackson School of Geosciences; University of Texas at Austin; Austin Texas USA
3. Now at Department of Earth and Planetary Sciences; Rutgers University; Piscataway New Jersey USA
4. Department of Earth Sciences; University of Minnesota; Minneapolis Minnesota USA
5. Institute for Rock Magnetism, University of Minnesota; Minneapolis Minnesota USA
6. Department of Marine and Coastal Sciences; Rutgers University; New Brunswick New Jersey USA
7. Department of Earth Sciences; University of California-Riverside; California USA
8. Now at Boone Pickens School of Geology; Oklahoma State University; Stillwater Oklahoma USA