by Douglas Paton, School of Psychology, Massey University, Palmerston North; David M. Johnston, Institute of Geological and Nuclear Sciences, Taupo; Mark S. Bebbington, Statistics, Institute of Information Sciences and Technology, Massey University, Palmerston North; Chin-Diew Lai, Statistics, Institute of Information Sciences and Technology, Massey University, Palmerston North; and Bruce F. Houghton, Department of Geology and Geophysics, University of Hawaii.