Model describes New Zealand's complex tectonic environment


  • Colin Schultz


At the Hikurangi fault, off the eastern coast of New Zealand's North Island, the Pacific tectonic plate sinks beneath the Australian plate. Farther south, in the Marlborough Fault System, which cuts through the country's larger South Island, the interaction between the two slabs turns such that the plates grind edge-on. From north to south, over a relatively short length of the plate boundary, the interaction switches from subduction to strike-slip. Though the fault systems near each of New Zealand's major islands have been studied extensively, the intervening region that harbors the transition between the two modes of interaction is much less well understood. Exploring the subduction-to-strike-slip transition region could help explain whether and, if so, how the fault systems that populate the country are connected and potentially improve estimates of seismic risk.