A dozen small earthquakes have rumbled northwest of Turangi on Wednesday afternoon, the latest in a series of quake swarms to set the area trembling.
Volcanologist Brad Scott said the area had a number of earthquake swarms in the past six weeks.
"It has been happening the whole time, but it's certainly restarted and picked up in tempo a little bit."
The earthquakes hit on Wednesday afternoon and ranged between magnitude 2.3 to 3.5, hitting mostly around 8km deep.
They commonly occur in volcanic areas, such as the central North Island.