GNS scientists are trying to find out how the legendary Pink and White Terraces survived the 1886 Tarawera eruption after announcing that traces of both terraces are now found.

It was widely thought the destructive eruption from nearby Mount Tarawera completely destroyed the terraces.

Sonar image showing horizontal scallop-shaped features on the bottom of Lake Rotomahana. Scientists believe it is a section of the White Terraces and say the white areas in the image represent the hard, reflective edges of the terraces. The dark areas indicate soft sediment and mud. The overall length of the feature is about 180. Image: Woods Hole Oceanographic Institution in the US.

A section of the Pink Terraces was found in January, but new evidence reveals part of the White Terraces, 60 metres under water, has also survived.

GNS volcano surveillance coordinator Brad Scott is working on the project to study Lake Rotomahana's submarine volcano hydrothermal system.

He says the aim of the project was never to find the terraces because it was assumed both had been destroyed.

Evidence of the White Terraces is based on sonar images from un-manned submarines.

Brad says the find is 'amazing”.

Painting of the Pink Terraces, with the White Terraces in the distance, by John Barr Clarke Hoyte (1835-1913). Alexander Turnbull Library.

'Most of us, from a volcanological perspective were pretty confident they had been destroyed.

'We were not expecting to find them. Because of the style of the eruption in 1886, the perception was that they would have been destroyed and for some obscure reason they have not been.”

When the Pink Terraces were found in January, scientists were able to get underwater images of the structure, but Brad is unsure if they can photograph the White Terrace.

He says the high-tech camera they were using at the time has been sent back to the United States.

'We're looking at the prospect of a stage two to come back and do additional work, but that's all dependent on obtaining funding.”

Only a small section of the White Terraces has been confirmed by sonar.

Brad estimates it is a 70m to 80m continuous section.

'It's one long and continuous piece, but in terms of the whole terrace it is a very small portion.”

Scientists are unsure if the rest of the terraces are destroyed or buried under silt and mud.