This document provides a high-level summary of the ground-motion characterisation model component of the 2022 New Zealand National Seismic Hazard Model. This includes: development of a New-Zealand-specific ground-motion database; consideration of alternative empirical ground-motion models based on global datasets; two new New-Zealand-specific models that were developed as part of the project; comparisons of the alternative models against observational data; and considered modifications of the ‘base’ models to account for near-fault directivity, back-arc attenuation for subduction...

A model is presented for predicting the distribution of logarithmic response spectral ordinates from crustal earthquakes in New Zealand. The model includes predictions of the mean logarithmic spectral amplitudes, the logarithmic standard deviation and epistemic uncertainty in both of these components. Three logic-tree branches are proposed for both the mean and standard deviation, leading to nine logic-tree branches overall. The weights assigned to each branch are provided as part of the model specification. The model...