1. Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada.
2. Department of Geological Sciences, Brown University, 324 Brook Street, Providence, RI 02912, USA.
3. Department of Terrestrial Magnetism, 5241 Broad Branch Road, Carnegie Institution of Washington (CIW), Washington, DC 20015, USA.
4. Geophysical Laboratory, 5251 Broad Branch Road, CIW, Washington, DC 20015, USA.
5. Advanced Light Source, Lawrence Berkeley Laboratory, Berkeley, CA 94720, USA.
6. Department of Physical Sciences, Grant MacEwan University, Edmonton, Alberta T5J 4S2, Canada.
7. School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
8. NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
9. Engineering and Science Contract Group, NASA Johnson Space Center, Houston, TX 77058, USA.
10. Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375, USA.