Nearly 300 small earthquakes have been recorded in the Taupo and Rotorua areas since Monday last week, according to Geonet.
Geonet seismometers between Taupo and Tongariro National Park recorded the swarm of earthquakes, which are centred about 10km northwest of Tokaanu, near Turangi.
Since the quakes started on February 13 at 6pm, there have been 290 tremors. The largest was a magnitude 3.8 at 9.35pm yesterday.
Geonet said earthquake swarms were a sequence of many earthquakes striking in a relatively short time in a localised area. They are different from normal earthquakes followed by aftershocks because no single earthquake in the sequence is obviously the main shock.
The largest quake can come anywhere in the sequence and the rate that earthquakes occur can also vary.
The Taupo Volcanic Zone grows wider each year by 6-9 mm. Geonet said the earthquakes were likely to be related to the long-term "tectonic" stretching of the zone.
Geonet said there were no indications the earthquakes were related to volcanic activity because they were well away from the active volcanoes.
It would continue to closely monitor the quakes.