Department of Earth and Space Sciences, University of Washington, Box 351310, Seattle, WA 98195, United States ; Geomagnetism Program, USGS, PO Box 25046, MS-966, Denver, CO 80225, United States
Geomagnetism Program, USGS, PO Box 25046, MS-966, Denver, CO 80225, United States
Earthquake Hazards Team, USGS, 345 Middlefield Road, Menlo Park, CA 94025, United States