Introduction to the Kaikōura earthquake special issue

Abstract

The Kaikōura Earthquake ruptured a complex network of at least 20 faults in the northeastern South Island, with variable geometries, slip and slip rates. Ground shaking and surface fault rupture generated a tsunami, thousands of landslides, and many dammed rivers. The earthquake damaged farmland, buildings and infrastructure in the northeastern South Island and Wellington regions, closing critical transport networks for over a year. This special issue presents a collection of 12 papers on the earthquake. These papers cover a range of topics, including, the geometries and paleoearthquake histories of faults that ruptured, seismic hazards, the tsunami and coastal geomorphology, together with the societal impact and communication of the earthquake. They incorporate our understanding of the earthquake 5–6 years since it occurred. Despite an unprecedented amount of data and thousands of published papers referring to the earthquake, many key questions remain. These include: is the Hikurangi subduction interface capable of producing great earthquakes beneath the northeastern South Island? Why did the Hope Fault not accommodate significant slip in the earthquake? Has the earthquake changed the seismic hazard in central Aotearoa New Zealand? Addressing these questions will improve understanding of seismic processes and hazards helping to build resilience to future earthquakes.