Researchers say they're close to discovering the location of the Pink and White Terraces, which were largely destroyed in the 1886 eruption of Mt Tarawera.

A 19th century diary and hand-drawn maps have led Niwa scientists to confirm the location of New Zealand's lost natural wonder - the Pink and White Terraces.

Niwa looked over the only known formal survey of Lake Rotomahana - 20 kilometres south-east of Rotorua - before the 1886 eruption of Mt Tarawera.

German-Austrian geologist Ferdinand von Hochstetter's survey included important details about the terraces, small geothermal features around the lake and some distant landmarks.

HOCKEN COLLECTIONS JC Hoyte's painting of the Pink and White Terraces in the 1870s, prior to the eruption of Mt Tarawera in 1886.

"Our research agrees with previous findings by Professor Ron Keam and GNS Science that the former sites of the terraces are under the modern Lake Rotomahana," Dr Andrew Lorrey said.

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The fabled Pink and White Terraces, also known as Te Otukapuarangi, were once dubbed the eighth wonder of the world and were a thriving tourist destination, attracting people from overseas.

NOLDEN NOLDEN 2013 Top: Digital elevation oblique view of Mount Tarawera and the surrounding landscape near Lake Tarawera based on von Hochstetter’s (1859) survey notes. Bottom: Watercolor and pencil sketch of the same view crafted by Ferdinand von Hochstetter April 1859.

The terraces formed over thousands of years as silica-rich water emerging from springs and boiling geysers crystallised into giant tiered staircases. The White Terrace covered more than three hectares while the smaller Pink Terrace was used for bathing on the lower levels. There was also a smaller, lesser known feature called Tuhi's Spring, or the Black Terrace.

They disappeared after the Mt Tarawera eruption which was the largest and most destructive in New Zealand since the early 19th century. It devastated the surrounding countryside, destroyed several villages and was responsible for about 120 deaths.

Lorrey and fellow Niwa scientist John-Mark Woolley evaluated von Hochstetter's diary notes and reconstructed his survey sites and stations around Lake Rotomahana using a remote sensing system that uses light pulses to measure distance and topography.

NOLDEN NOLDEN 2013 Sketch map of Rotorua by Ferdinand von Hochstetter that encapsulates major landforms in the region.

They combined that information with sketches drawn by von Hochstetter and a map published in 1862 to pinpoint the former location of the terraces.

Von Hochstetter's notes contained several other draft maps which were progressively refined as he worked.

"You can see how he reconsidered two or three times how to draw things and how to orientate them," Lorrey said.

GNS SCIENCE The Pink and White Terraces were buried underneath Lake Rotomahana, south of Rotorua, by the Mt Tarawera eruption in 1886.

"The published map is faithful to the diary measurements, and the results we obtained align to previous research on where the terraces might be."

The outcome demonstrated the accuracy and utility of historic documents for scientific research, he said.

The latest research by Niwa was carried out at the request of Tūhourangi Tribal Authority following conflicting findings about the former location of site.

The eruption of Tarawera was so violent it was heard in Auckland and in the South Island. It left a 17km-long gash through Mt Tarawera and south-westward beneath the lake. After the eruption, the lake level rose at least 60 metres and its area grew about five times.

GNS scientist Cornel De Ronde talked about the eruption and its impact in a 2011 YouTube video.

In August, GNS Science researchers claimed the white terraces were largely destroyed, while remnants of the pink terraces may lie at the bottom of the lake.

The new Niwa results have been published today in scientific journal Frontiers of Earth Science.