A fault line is a resultant fracture caused by the movement of the Earth's crust. Major faults in New Zealand would include the North Island Fault System and the Alpine Fault.
The North Island Fault System is a major plate boundary found in the North Island and is subject to constant stress, generated by the movement between the Australian and Pacific plates.At the North Island, the Pacific plate is moving towards and subducted beneath the Australian plate. Deep earthquakes at North Island form a well defined seismic zone.
The South Island houses the Alpine Fault, which carries most of the plate boundary strain. Along the Alpine Fault, plates are sliding past each other and also moving towards one another. The main part of South Island is thrust over the Australian Plate on a bearing of about 250 degrees. The compressional forces result in the uplifting of Southern Alps at a rate hovering around 7 millimetres per year and subsequently forming a high, elongated mountain range that runs parallel to the Alpine Fault.
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| Records of notable shallow earthquakes in New Zealand |
