November's Kaikoura earthquake also triggered a series of deep-seated, unfelt "slow-slip" earthquakes in the North Island. What are called "slow-slip" events are very similar to earthquakes, because they involve more-rapid-than-normal movement between two pieces of the Earth's crust along a fault. But unlike earthquakes, where the movement occurs in seconds, shifts in these "silent earthquakes" can take weeks or months to occur. The east coast slow-slip event was also responsible for sparking a series of small to moderate earthquakes off the east coast last November. The scientists are planning to produce separate research papers on the post-earthquake slip on the subduction zone beneath the Kapiti and Marlborough regions, once those events finish.

Source: Otago Daily Times September 11, 2017 20:26 UTC