The 2022 revision of Aotearoa New Zealand National Seismic Hazard Model (NZ NSHM 2022) has involved significant revision of all datasets and model components. In this article, we present a subset of many results from the model as well as an overview of the governance, scientific, and review processes followed by the NZ NSHM team. The calculated hazard from the NZ NSHM 2022 has increased for most of New Zealand when compared with the previous models. The NZ NSHM 2022 models and results are available online.

The region in and around Christchurch, encompassing Christchurch city and the Selwyn and Waimakariri districts, contains more than 800 road, rail, and pedestrian bridges. Most of these bridges are reinforced concrete, symmetric, and have small to moderate spans (15–25 m). The 22 February 2011 moment magnitude (M_w) 6.2 Christchurch earthquake induced high levels of localized ground shaking (Bradley and Cubrinovski 2011, page 853 of this issue; Guidotti et al. 2011, page 767 of this issue; Smyrou et al. 2011, page 882 of this issue), with damage to bridges mainly confined to the central...

The 2016 $Mw$ 7.8 Kaikōura earthquake caused widespread liquefaction and significant ground movements in thick end‐dumped gravelly fills and hydraulically placed dredged sandy fills at CentrePort, Wellington. Settlement of 200–300 mm occurred throughout the reclamation, and settlement as large as 400–600 mm occurred near the reclamation edges where lateral movements on the order of 0.5–1.5 m occurred, which in turn damaged wharves and structures. Ground motions and damages at the port produced by the 2013 $Mw$ 6.6 Cook Strait and the 2013 $Mw$ 6.6 Lake Grassmere earthquakes are compared with those caused by the 2016 $Mw$ 7.8 Kaikōura earthquake. The documentation of liquefaction manifestations and surveys of ground movements followed by comprehensive subsurface investigations performed after the Kaikōura earthquake characterized the different fill materials at the port and the underlying marine sediments and Wellington Alluvium layers, as well as key aspects of the port’s seismic performance. The cone penetration test data together with the grain‐size composition of the fills indicate the finer sand–silt fractions of the well‐graded gravelly fill had a critical influence on the liquefaction resistance and performance of the gravelly fill during the Kaikōura earthquake. Key insights are shared through examination of this case history involving the liquefaction of gravelly soils.

This article summarizes the development of the 2023 New Zealand ground-motion database (NZGMDB). A preceding version was formally used as the central ground-motion database in the ground-motion characterization modeling for the 2022 New Zealand (NZ) National Seismic Hazard Model (NSHM) revision. The database contains ground motions for events with a moment magnitude greater than ∼3.0 from the years 2000 to the end of 2022. Several challenges associated with NZ earthquake source metadata are explained, including determination of earthquake location, magnitude, tectonic classification, and finite-fault geometry, among others. The site table leverages the site database developed as a part of the 2022 NZ NSHM revision, and several definitions of source-to-site distance are computed for the propagation path table. The ground-motion quality classification was initially assessed using a neural network. Subsequent waveform quality verification was conducted and additional quality criteria were enforced to ensure a sufficiently high-quality database. Standard processing techniques were applied to the ground motions before intensity measure (IM) calculation. IMs in the database include peak ground acceleration, 5%-damped pseudoacceleration response spectra, smoothed Fourier amplitude spectra, and other cumulative and duration-related metrics. The NZGMDB is publicly available and routinely updated as new and higher quality data become available.