Lake Taupō. Photo: RNZ / Rebekah Parsons-King
It is one of the furthest places from the ocean in New Zealand.
But in the middle of the night in 2022, a tsunami in Lake Taupō flooded the foreshore, damaging moored boats. The trigger was a 5.6 magnitude earthquake caused by unrest in the volcano beneath the lake.
GNS Science volcano seismologist Dr Oliver Lamb told Afternoons the tsunami was caused by a "pretty unusual earthquake".
The Taupō tsunami
"When people think of earthquakes, the classic model we see is ... two large lumps of rocks moving past each other," he said.
"That's not what we think happened on this night in November 2022. What we think actually happened was a special kind of earthquake, quite rare, it's only been seen in a few other volcanoes around the world, called a trap door earthquake.
Trap door earthquakes were large sections of earth behind the lake moving up, like a trap door, explained Lamb.
He and his team have about a dozen seismometers around the lake which provide them with data to study.
Lamb said learning as much as they could about the volcanic activity would help the region be better prepared when the volcano erupts again.
Cracked and slumping soil on the shore of Lake Taupō after the 30 November earthquake. Photo: Geonet
"Taupō [has] an active volcano, it has erupted in the past and it will definitely erupt again in the future," he said.
The last big eruption of the volcano in Lake Taupō was 1800 years ago.
"The reason why we do this, is we want to understand what's happening in the volcano during each unrest episode and each unrest episode, the earthquake teaches us new things about the volcano.
Lamb said through studying the data, they would be able to give better advice to the public.