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 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.
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 recently 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."