Murray Hoggett, University of Birmingham, Birmingham, B15, United Kingdom, Chisomaga Opara-Nestor, University of Birmingham, Birmingham, United Kingdom, Timothy J Reston, University of Birmingham, School of Geography, Earth and Environmental Sciences, Birmingham, B15, United Kingdom, Christine Peirce, University of Durham, Durham, United Kingdom, Richard W Hobbs, University of Durham, Department of Earth Sciences, Durham, United Kingdom and Christopher J MacLeod, Cardiff University, Cardiff, United Kingdom