Lee RL, Bradley BA, Manea EF, Hutchinson J. 2022. Evaluation of empirical ground-motion models for New Zealand application. Lower Hutt (NZ): GNS Science. 141 p. (GNS Science report; 2021/61). doi:10.21420/W2M5-YC09.
Abstract
This report presents an evaluation of empirical ground-motion models for shallow crustal, subduction interface and subduction slab earthquakes using a recently developed New Zealand ground-motion database. The evaluation considers both New-Zealand-specific and international models, which require validation to ensure their applicability in a New Zealand context. A quantitative comparison between the models is undertaken based on intensity measure residuals and a mixed-effects regression framework. The results are subsequently investigated to assess how the models are performing in terms of overall accuracy and precision, as well as to identify the presence of any biases in the model predictions when applied to New Zealand data. Comparisons of important earthquake scenarios that are outside of the validation dataset parameter space are also examined. Ultimately, many models showed reasonable performance and could be considered appropriate to include within suites of models to properly represent ground-motion predictions and epistemic uncertainty. In general, recent models that are New-Zealand-specific or developed on large international databases performed best. This evaluation of models is expected to provide guidance and inform decisions in seismic hazard modelling, including choice of probabilistic seismic hazard analysis logic-tree weights. (The authors)
