Dept. Earth and Space Sciences, University of Washington, Box 351310, Seattle, WA 98195-1310 United States; Physics Department, University of Washington, PO Box 351560, Seattle, WA 98195-1560 United States
Dept. Earth and Space Sciences, University of Washington, Box 351310, Seattle, WA 98195-1310 United States
Dept. Earth and Space Sciences, University of Washington, Box 351310, Seattle, WA 98195-1310 United States
Low Frequency Electromagnetic Research, Ltd, 161 Pine Hill Road, Dunedin, 9001 New Zealand
Department of Physics, University of Otago, PO Box 56, Dunedin, none New Zealand
DGE/INPE, Av. Astronautas 1758, Sao Jose dos Campos, SP 12227-010 Brazil