Were they still around today, the Pink and White Terraces of New Zealand would likely share court with such natural attractions as the Grand Canyon, Great Barrier Reef and Victoria Falls. These two stunning geological formations, formed over thousands of years, were regarded by many as the eighth wonder of the world, inspiring tourists in the 19th century to make extraordinary journeys to witness their beauty.
From geological surveys, eyewitness accounts, paintings and few rare photographs, we know that those lucky enough to have experienced the terraces enjoyed a unique jewel of nature. Both the Pink and White, separated by 2,600 feet, were formed from two large geysers above the shores of Lake Rotomahana on New Zealand's North Island. It's estimated that the terraces were the largest formations of silica sinter, a fine-grained type of quartz, ever seen on Earth.
In the early hours of June 10, 1886, the brief awe and wonder the terraces enjoyed from humanity came to a sudden, violent end. The three peaks of Mount Tarawera, one of several active volcanoes in the region, erupted with a force that ripped open the bottom of Lake Rotomahana, buried the landscape, and killed more than 150 people.
The Pink and White Terraces vanished under a wave of ash, mud and debris,with a crater more than 300 feet deep appearing in their place. Over time, this gash filled with water to form the new boundaries of Lake Rotomahana. This likely wonder of the world was no more.
Or was it?
In 2011, 125 years after the terraces' disappearance, scientists from New Zealand and the United States embarked on a collaborative study of the volcanic activity under Lake Rotomahana. While the primary purpose was to map the lake's floor and its geothermal systems, the researchers were also privately hopeful that they might see glimpses of whatever remained of the terraces.
Those dreams were quickly realized when the team deployed high-resolution side-scan sonar to examine a portion of the lake where the Pink Terraces once existed. After examining the images, they found unusual hard, crescent-shaped structures jutting out onto the lake bed. An examination of the underwater terrain consistent with the location of the White Terraces revealed the same ghostly remains.
"The rounded terrace edges are standing up from the lake floor by about a metre in some places," Project Leader Cornel de Ronde said in a release. "The sonar images of both sets of terraces are strikingly similar."
While the rest of the Pink and White Terraces may be buried under too much sediment for side-sonar technology to penetrate, de Ronde speculates that the more likely conclusion is that they were destroyed by the eruption. "However, we found tantalizing evidence from underwater photographs and side-scan sonar that remnants of both sites survived," he told Stuff.co.nz.
In a collection of papers published on the five-year study of Lake Rotomahana in a special issue of the Journal of Volcanology and Geothermal Research, the researchers also revealed the fate of the two geysers that created the magnificent terraces. While the one that fed the White Terraces has ceased, the other under the Pink Terraces continues to show vigorous activity –– the first-ever example of an "on-land" geothermal system surviving a volcanic eruption, sinking underwater, and continuing to function.
"This project has been a unique opportunity to apply a lot of investigative technology in the study of a drowned geothermal system," added de Ronde. "It was truly a pleasure to do this work and we hope we have left a legacy contributing to the history of this famous landmark."
The 'X' on the map may have moved
Based on the findings outlined above, researchers have operated under the assumption that the Pink and White Terraces were destroyed, but what if everyone was just looking in the wrong place?
That's what two researchers are suggesting in a paper published in the June 2017 issue of the Journal of the Royal Society of New Zealand. Using a 19th century diary, independent researcher Rex Bunn and Sascha Nolden, a research librarian at the National Library of New Zealand, tracked geographical changes from 1859, when the diary was written, and today. They theorize that the Mount Tarawera eruption was so powerful that it shifted the landscape, including where we think the terraces are located.
How did Bunn and Nolden come to this idea? The diary, written by the geologist Ferdinand von Hochstetter, outlines his account of a geographical survey of the islands he conducted at the behest of the New Zealand government in 1859. In those notes, von Hochstetter provided an account of Lake Rotomahana's location and had the Pink and White Terraces clearly marked away from the lake itself, and as such, were further inland than had originally been thought.
Basically, Bunn and Nolden argue, we've been looking under a lake when we should've been looking underground.
Using a technique called forensic cartography to make this determination, Bunn and Nolden spent 2,500 hours over the past year to plot out where von Hochstetter would have stood to make his 19th-century recordings and compared that data to current topographical features to determine the location and scale necessary to see how the landscape would have shifted.
How close do Bunn and Nolden think they are? Plus or minus 35 meters, or about 117 feet.
"We're closer than anyone has ever been in the last 130 years," Nolden told Stuff.
He and Bunn have mad a request for an excavation to take place in the area they've identified, and the local Tuhourangi tribal authority will make the final decision about whether or not a dig occurs.
This story was originally published May 2016 and has been updated with new information.