Affiliation: | (1) Geographic Information and Analysis Center, Department of Earth Sciences, Montana State University, Bozeman, MT 59717-3495, USA (e-mail: aspinall@montana.edu), US;(2) Department of Geography, University of Oregon, Eugene, OR 97403-1251, USA (e-mail: marcus@oregon.uoregon.edu), US;(3) Analytical Imaging and Geophysics LLC, 4450 Arapahoe Avenue #100, Boulder, CO 80303, USA (e-mail: boardman@aigllc.com), US |