1. School of Geography, Earth and Environmental Sciences, University of Plymouth, PL4 8AA, UK
2. Department of Geography and Environmental Studies, Central Michigan University, Mount Pleasant, Michigan 48858, USA
3. School of Education and Department of Geology, University of Cincinnati, Cincinnati, Ohio 45221, USA
4. Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4