1. 1 Norman B. Keevil Institute of Mining Engineering, University of British Columbia, 517-6350 Stores Road, Vancouver, British Columbia V6T 1Z4, Canada
2. 2 School of Public Policy and Global Affairs, University of British Columbia, 6476 NW Marine Dr., Vancouver, British Columbia V6T 1Z2, Canada
3. 3 Department of Earth, Ocean and Atmospheric Sciences, Faculty of Science, 2020-2207 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
4. 4 Institute for Resources, Environment and Sustainability, University of British Columbia, 429-2202 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada