1. James Franck Institute and Department of Physics; University of Chicago; Chicago Illinois USA
2. Department of Natural Sciences; University of Alaska Southeast; Juneau Alaska USA
3. Department of Earth Sciences; University of New Hampshire; Durham New Hampshire USA
4. Geophysical Institute; University of Alaska Fairbanks; Fairbanks Alaska USA
5. Jackson School of Geosciences and Institute for Geophysics; University of Texas at Austin; Austin Texas USA