An international team of scientists looked at how far fires could spread if sparked by a volcanic eruption.
The recent number and size of earthquakes is within GeoNet's expectations for a volcano at minor volcanic unrest.
"In the event of the Hunga eruption [it] showed that there's a lack of early warning from international tsunami warning systems and models."
An international study suggests New Zealand is underestimating the damage caused by volcanoes.
The night sky above Hawaii's largest island glowed a hellish red as bright, hot lava sprang forth at the volcano's summit.
The eruption of Hunga-Tonga Hunga-Ha'apai caused 10 cubic kilometres of seafloor to be displaced.
Last week, GeoNet upgraded Lake Taupō's volcanic unrest alert level from zero to one for the first time ever.
Lake Taupō has been shaken by 40 tremors a week since May, and 700 overall since January.
Taupō's volcano alert level was earlier raised to 1 for the first time following minor volcanic unrest.