The shake felt by many Tauranga residents early yesterday morning would have been the 7.5 magnitude earthquake centred near Hanmer Springs, a scientist says.
GNS Science seismologist John Ristau said the quake, which struck about 15km northeast of Culverden at 12.02am, was the result of what was called thrust faulting, a type of reverse faulting.
Scientists also believed the event may have not been one quake, but two.
GeoNet reports indicated the combination of the two largest quakes lasted two minutes, with the most severe shaking continuing for about 50 seconds.