1. School of Earth Sciences, University of Western Australia, Crawley WA 6009, Australia
2. CSIRO Land and Water, Private Bag No. 5, Wembley WA 6913, Australia
3. Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, 10964, USA
4. Center for Applied Geoscience, University of Tübingen, Tübingen, Germany