Fault-Landslide Interactions: Examples from the 2016 M7.8 ‘Kaikōura’, New Zealand, Earthquake

The surface rupture generated by the 14th November 2016 M7.8 ‘Kaikōura’ earthquake ruptured multiple faults over a distance of approximately 200 km. The southern extent of the rupture in northern Canterbury displays a remarkable complexity of rupture style, geometry and surface expression. Much of the surface trace is closely associated with a number of large, complex mechanism coseismic landslides. The spatial proximity of landslides and fault rupture through a region of elevated topography has resulted in areas where the determination of the origin of surface deformation features becomes difficult. The identification of primary fault rupture is vital for surface rupture hazard determination, especially for the development of fault avoidance and setback zones. We present the results of detailed field investigations showing the relationships between primary and secondary surface faulting and areas of slope failure. The geomorphological characteristics of each deformation mechanism are discussed, and approaches to developing criteria for distinguishing the origin of upland surface deformation are presented.