[1] Univ Western Australia, Sch Earth & Geog Sci, Crawley, WA 6009, Australia
[2] Curtin Univ Technol, Sch Appl Phys, John de Laeter Ctr Mass Spectrometry, Bentley, WA 6102, Australia
[3] Minist Civil Def & Emergency Management, Team Leader Hazard Risk Management & Res, Dept Internal Affairs, Wellington, New Zealand