1. 1U.S. Geological Survey, 2255 North Gemini Drive, Flagstaff, Arizona 86001, USA
2. 2U.S. Geological Survey, 632 SW Hall Street, Portland, Oregon 97201, USA
3. 3Department of Geosciences, Colorado State University, 1482 Campus Delivery, Fort Collins, Colorado 80523, USA
4. 4U.S. Geological Survey, P.O. Box 158, Moffett Field, California 94035, USA
5. 5The University of Texas at Austin, Jackson School of Geosciences, 2305 Speedway, Stop C1160, Austin, Texas 78712, USA
6. 6U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, USA
7. 7School of Earth and Sustainability, Northern Arizona University, Flagstaff, Arizona 86011, USA