Institution: | Department of Geosciences, Virginia Tech, 4044;Derring (0420), Blacksburg, VA 24061, USA Department of Geosciences, Virginia Tech, 4044;Derring (0420), Blacksburg, VA 24061, USA. E-mail: Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241;Broad Branch Rd. NW, Washington, DC 20015, USA |