1. Acoustics Research Group, Department of Physics and Astronomy, Brigham Young University, N283 Eyring Science Center, Provo, Utah 84602, USA
2. Detonation Science and Technology Group (Q-6), Los Alamos National Laboratory, MS C925, Los Alamos, New Mexico 87545, USA
3. Geophysics Group (EES-17), Los Alamos National Laboratory, MS D446, Los Alamos, New Mexico 87545, USA