A swarm of nearly 50 small earthquakes have been recorded near Kawerau this morning.
GNS Science volcanologist Brad Scott said the first was recorded at 5am, and 46 had been located since, all in the area 15km South-West of Kawerau.
He said there had been more, but they were too small to locate.
The earthquakes ranged in magnitude from 1.2 to 3.7 which Scott said was not big, but had been reported as 'felt' by 173 people.
He said swarm activity like this was "really typical" for the Taupo Volcanic Zone and was nothing to be concerned about.