1. Department of Civil and Natural Resources Engineering, University of Canterbury , Christchurch 8140 , New Zealand
2. Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences , Potsdam 14473 , Germany
3. Institute of Geosciences, University of Potsdam , Potsdam 14482 , Germany
4. Disaster Prevention Research Institute, Kyoto University , Kyoto 611-0011 , Japan