Photo:
GeoNet has increased the alert level for the volcano below Lake Taupō for the first time, after a swarm of quakes around the lake this year.
The super-volcano has been rattled by 40 tremors a week since May, and 700 overall since January.
The volcano caused the largest eruption on Earth in the past 5000 years when it last exploded about 1800 years ago.
Dr Finn Illsley-Kemp is a volcano seismologist at Victoria University of Wellington.
