Earthquake-induced landslides and landscape dynamics: The 2016 Kaikōura Earthquake and response
The Mw 7.8 Kaikōura earthquake was a complex one, rupturing ~20 faults on and offshore including several that had not been recognised as active. It also generated tens of thousands of landslides, hundreds of landslide dams and damaged hillslopes that are now susceptible to failure during rainstorms and aftershocks. The landslide debris, when mobilised, will create new hazards – further landsliding, rapid aggregation, increased river channel instability and will threaten infrastructure into the future. Several large landslides closed State Highway 1 along the Kaikōura coast for over a year forcing major changes to New Zealand’s main transport route from Wellington to Christchurch. The road has reopened but repair work continues and it remains vulnerable to further disruption and closures.
These hazards are likely to persist for years to decades, requiring active management but also providing researchers with a natural laboratory with which to quantify post-earthquake landscape dynamics. Researchers in New Zealand and their overseas colleagues started to collect perishable data immediately after the earthquake and are continuing to do so. Repeat LiDAR surveys, ground profiling, field monitoring, laboratory testing and numerical modelling will be integrated to determine how hillslopes and rivers will respond to future forcing events. The goal is to produce an integrated set of predictive tools to manage earthquake and post-earthquake landslide risk.