Nicholas Thomas Hitt, Victoria University of Wellington, School of Geography Environment and Earth Sciences, Wellington, New Zealand, Daniel J Sinclair, Victoria University of Wellington, Wellington, New Zealand, Helen Neil, National Institute of Water and Atmospheric Research, Wellington, New Zealand, Stewart Fallon, The Australian National University, Research School of Earth Sciences, Canberra, Australia, Aimee K Komugabe-Dixson, The Australian National University, Acton, Australia and John Charles Hellstrom, University of Melbourne, School of Earth Sciences, Parkville, VIC 3010, Australia