Archaeologists say a 3D model of a centuries-old quarry of unfinished stone statue heads on Easter Island provides new clues about how the monuments were created and Polynesian society it brought them into existence.
This remote island, also known as Rapa Nui, is famous for its giant sculptures overlooking the Pacific Ocean, but its residents have never erected what would have been the community's largest statue. The giant head, along with hundreds of others, remains in the rock of the quarry, a volcanic crater.
According to a study published Wednesday in PLOS One magazine.
“The scale seemed to require central coordination,” said study co-author Carl Lipo, a professor in the department of anthropology at Binghamton University in New York. “The presence of monuments became circular evidence of hierarchy. Monuments meant leaders, because leaders built monuments.”
To analyze the object, the researchers created what they called the first high-resolution image. 3D model the moai quarry of Rano Raraku, based on 11,000 overlapping images taken by drone in a process known as photogrammetry.
The quarry model identified 426 moai in various stages of completion. – Carl P. Lipo/Binghamton University; Terry L. Hunt/University of Arizona
The scientists identified 30 different sites of quarry activity, which they say indicate the presence of multiple independent work zones. The team also found evidence of the moai being transported from the quarry in different directions before they were installed on huge platforms scattered across the island.
This approach, the authors argue, also indicates that the production of megalithic figures was not under central control.
“This means that the entire production chain—from the first cut in the rock to the final pieces of the statue—remained in separate zones, rather than moving statues between sites at different stages of production,” as would be the case in an industrial quarry, Lipo said by email.
He added that there are differences in mining methods and finishing techniques in different zones. This pattern adds to the evidence that Rapa Nui was not a politically unified society, but instead consisted of small and independent family groups.
Massive head statues on Easter Island
The model provides a fresh look at the monumental event that took place on the tiny island, where around 1,000 stone statues were erected between the 13th and 17th centuries. According to Lipo, the average statue was 4 meters (13 ft) tall and weighed 12.5 tons, with some exceeding 20 tons.
Moai statues dot the hillside at the Rano Raraku quarry on Easter Island. – Oliver Ferstner/imageBROKER/Shutterstock
The quarry model revealed 426 moai in various stages of completion, 341 trenches cut along the contours of the carving blocks, and 133 cavities in the rock from which statues were successfully removed, as well as five pillars that served as anchor points for the moai to be lowered down the slopes. Craftsmen quarried and carved most of the statues in a prone position, with most carved from top to bottom, although others were excavated from the side. The most common method was to determine the details of the face before outlining the head and body on the stone.
According to Lipo, among the unfinished statues is what could be the largest moai if it were completed and installed. It is known as Te Tokanga, is about 21 meters (69 feet) tall and would weigh about 270 tonnes, he said.
“Some statues exceed the practical limits of transportation,” Lipo said. “This would be the case if, as we suspect, escalating competition caused communities to attempt to create even larger moai. These overreaches represent testing communities' limits and recognizing limitations.”
The numerous statues remaining at Rano Raraku symbolize normal operation of the quarry rather than abandonment, Lipo added. A 2019 study suggested that statue production continued until the arrival of Europeans, he noted.
“The quarry did not suffer a catastrophic failure, but was most likely stopped due to destruction caused by Europeans caused by the spread of disease,” he said.
The latest study was the first time photogrammetry techniques were used at the site, but the results did not show anything fundamentally new about Rapa Nui society, said Helen Martinsson-Wallin, a professor in the department of archeology at Uppsala University in Sweden. Martinsson-Wallin, who was not involved in the study, said scientists such as the English archaeologist and anthropologist Catherine Rutledge defined the clan system 100 years ago.
“It was later defined as a so-called open society, which means that there is no paramount leader in the society, and several studies showed that this type of social structure could also exhibit megalithic building structures,” Martinsson-Wallin said by email.
The study took an “innovative approach,” said Christopher Stevenson, an archaeologist and professor at Virginia Commonwealth University's School of World Studies, who also was not involved in the study. He added that the team's hypothesis that the quarry activity represents decentralized moai production by various kin groups is “an important one that needs to be assessed.”
However, Stevenson said the researchers' assessment was not supported by sufficient data. For example, he said there is a house near the quarry, not mentioned in the study, that is different from less complex residential buildings and therefore may reflect some kind of social division or difference.
Fierce debate over Rapa Nui society
The average statue was 4 meters (13 ft) high and weighed 12.5 tons. – Carl P. Lipo/Binghamton University; Terry L. Hunt/University of Arizona
Easter Island, now part of Chile, settled by a small group of Polynesian sailors about 900 years ago, has long been a source of fascination and fierce debate about how complex societies can sometimes lead to devastating collapse.
Some writers, such as geographer Jared Diamond in his 2005 book: “Collapse: How Societies Decide to Fail or Succeed,” used Easter Island as a cautionary example of how exploitation of limited resources can lead to catastrophic population decline, environmental devastation, and cultural destruction through civil strife.
This theory remains controversial. More recent study suggested the opposite: Rapa Nui was in fact home to a small but resilient society.
The latest findings contribute to this new interpretation, adding to the picture of a resilient community that has adapted to one of Earth's most isolated environments, Lipo said.
“The traditional story, popularized by Diamond and others, suggests that powerful chiefs oversaw unsustainable monument construction, which led to deforestation, agricultural decline and a demographic crisis,” Lipo said.
“But if monument production were decentralized and autonomous communities made independent decisions, there would be no central authority that could push the island off the ecological cliff.”
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