The Axial Tectonic Belt is by far the most active tectonic province of New Zealand. It extends across both islands, from Fiordland through the Southern Alps, Marlborough and the eastern North Island. It includes the most important fault systems in New Zealand, in particular the Alpine Fault along the Southern Alps, Hope Fault in Marlborough, and the North Island Shear Belt.
Cover image: the Glenroy River in the Nelson Lakes National Park flows northwards along the Alpine Fault, New Zealand's grand onshore boundary between the Australian and Pacific tectonic plates. The igneous Mt Cann, centre left, is on the Australian plate. The more easily eroded metamorphic rocks on the Pacific plate (right) have developed fans of erosion debris at the foot of the gullies which have pushed the river westward against the igneous rocks.

The Nelson-Westland tectonic province is located north-west of the Alpine fault. It contains a set of faults and has seen the occurrence of numerous and major earthquakes in the last century and a half, although this is considered to be unusual in a longer historical perspective.

The Taupo Volcanic Zone has been the most active volcanic area of New Zealand since the last 1.6 million years. It is the direct result of the subduction of the Pacific plate below the North Island. This is an area of high rates of shallow earthquakes, where the earth's crust has been 'spreading' and thinning , and has subsided by 2-3 km along a large rift.

New Zealand's tectonic provinces
After J.J. Aitken: Plate Tectonics for Curious Kiwis