[1] School of Geoinformatics, Planning and Building, University of South Australia, Adelaide,SA,5001, Australia
[2] Institute of Geological and Nuclear Sciences, P.O. Box 30-368, Lower Hutt, New Zealand
[3] Department of Geospatial Science, RMIT University, GPO Box 2476V, Melbourne,VIC, Australia
[4] Lamont-Doherty Earth Observatory of Columbia University, Palisades,NY,10964, United States