Hats on for Easter Island statues

Hats on for Easter Island statues
Diagram of pukao emplacement scenario that is supported by analysis of pukao form and the physics associated with pukao transport. Credit: Sean Hixon

How do you put a 13-ton hat on a giant statue? That's what a team of researchers is trying to figure out with their study of Easter Island statues and the red hats that sit atop some of them.

"Lots of people have come up with ideas, but we are the first to come up with an idea that uses archaeological evidence," said Sean W. Hixon, graduate student in anthropology, Penn State.

Rapa Nui —Easter Island, Chile—sits in the Southern Pacific Ocean more than 2,000 miles from Chile in South America. The island is about 15 miles long and 7.6 miles wide at its widest with an area of about 63 square miles. According to the researchers, the island was first inhabited in the 13th century by Polynesian travelers.

The statues, carved from volcanic tuff, came from one quarry on the island, while the hats, made of red scoria, came from a different quarry 7.5 miles away on the other side of the island.

Previous research by Carl P. Lipo, professor of anthropology, Binghamton University, and Terry Hunt, professor of anthropology and dean of the Honors College, University of Arizona, determined that the statues, which can be up to 33 feet tall and weigh 81 tons, were moved into place along well-prepared roads using a walking/rocking motion, similar to the way a refrigerator is moved.

"The statues were moved in a fashion using simple physics-based processes in a way that was elegant and remarkably effective," said Lipo. Not all statues made it to their final locations, and the fallen and/or broken ones showed that, to move them, the statues were carved so they leaned forward and were later leveled off for final placement.

The hats, with diameters up to 6.5 feet and weighing 13 tons, might have been rolled across the island, but once they arrived at their intended statues, they still needed to be lifted onto the statues' heads. The islanders probably carved the hats cylindrically and rolled them to the statues before further carving the hats to attain the final shapes, which vary from cylindrical to conical and which usually have a smaller cylindrical projection on the top. Chips of red scoria are found in the platform of some of the statue hat combinations.

Hats on for Easter Island statues
Restored statue platform with standing moai on the south coast of Rapa Nui. Note that one of the moai is adorned with a red scoria pukao. Credit: Sean Hixon

"We were interested in figuring out the method of hat transport and placement of the hats that best agrees with the archaeological record," said Hixon.

The researchers took multiple photographs of many Rapa Nui hats to see what attributes of the hats were the same throughout. Using photogrammetry and 3-D imaging, they created images of the hats with all their details.

"We assumed they were all transported and placed in the same way," said Hixon. "So we looked for features that were the same on all the hats and all the statues."

The only features they found the same were indentations at the bases of the hats, and these indentations fit the tops of the statues' heads. If the hats had been slid in place on top of the statues, then the soft stone ridges on the margin of the indentations would have been destroyed. So the islanders must have used some other method.

Previous researchers suggested that the statues and the hats were united before they were lifted in place, but the remnants of broken or abandoned statues, and other evidence for walking the statues, indicates this was not the approach used and that the hats were most likely raised to the top of standing statues.

Many of the hats left around the island are much larger than those placed on statues.

"The best explanation for the transport of the pukao (hats) from the quarry is by rolling the raw material to the location of the moai (statues)," said Lipo. "Once at the moai, the pukao were rolled up large ramps to the top of a standing statue using a parbuckling technique." Parbuckling is a simple and efficient technique for rolling objects and is often used to right ships that have capsized. The center of a long rope is fixed to the top of a ramp and the two trailing ends are wrapped around the cylinder to be moved. The rope ends are then brought to the top where workers pull on the ropes to move the cylinder up the ramp.

Hats on for Easter Island statues
Rano Raraku Statue Quarry and Puna Pau Pukao Quarry" Location of red scoria pukao quarry at Puna Pau (green square) and moai quarry at Rano Raraku (black square). Green circles mark locations of pukao . Credit: Sean Hixon

Besides reducing the force needed to move the hats, this arrangement also makes it easier to stabilize the hat on the trip up because the hat typically will not roll back down the slope. The researchers report in the current issue of the Journal of Archaeological Science, that 15 or fewer workers could move the largest preform hats up the ramps.

Once the hat was at the top of the ramp, it could not simply be pushed into place because of the ridges on the margin of the hat base indentation. Rather, the researchers believe that the hats were tipped up onto the statues.

First the hat would be modified to its final form, some including a second, smaller cylindrical piece on top.

The hats could be rotated 90 degrees and then levered up with small wooden levers to sit on the statue tops, or the ramp could be slightly to the side, so that rotation in the small space at the top of the ramp would be unnecessary. Then the hat would simply be levered and pivoted on edge and into place.

The ramps were then disassembled and became the wings of the platform surrounding the statues.

"This is the first time anyone has systematically explored the evidence for how the giant hats were placed on the top of the heads of the massive statues of Easter Island," said Lipo. "Our work combines cutting-edge 3-D modeling with artifact analysis and models drawn from physics to arrive at the best answer."

Explore further

Easter Island had a cooperative community, analysis of giant hats reveals

More information: Sean W. Hixon et al, The colossal hats ( pukao ) of monumental statues on Rapa Nui (Easter Island, Chile): Analyses of pukao variability, transport, and emplacement, Journal of Archaeological Science (2018). DOI: 10.1016/j.jas.2018.04.011 , dx.doi.org/10.1016/j.jas.2018.04.011
Citation: Hats on for Easter Island statues (2018, June 4) retrieved 18 July 2019 from https://phys.org/news/2018-06-hats-easter-island-statues.html
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Jun 04, 2018
I have noticed that these 'hats' look a whole lot like baggage on top of these people's heads, as if that is all they were able to carry with them when the lower lands flooded near the end of the last ice age, forcing the people, with only what they could carry, up the mountains that were not being flooded. And then the statues to commemorate the event and to tel future generations to Watch The Sky for Meteor and Cometary impacts. As have clearly happened before, and surely been the destruction of at least one civilization here on this planet.

Jun 04, 2018
Okay Steelwolf, I'll bite! What so-called civilization was destroyed? And what evidence do you have it was caused by "comets/asteroids? Aside from the badly translated drunken gibberish that passes for world religions, fractured fairytales and comicbooks?

If your speculation that the natives intent was to portray carrying burdens and not hats? Well, that is actually a reasonable guess. Even today you can see people carrying products to market on their heads.

But I am disappointed that still, no evidence of flying saucers! Our fictional entertainments promised us flying saucers!


Jun 04, 2018
@rrwillsj: I've been experimenting with flying saucers. They don't work very well and I've had lots of crashes. Her indoors isn't amused.

Jun 04, 2018
pulleys, multiple ropes lift and swing, effortless

Jun 04, 2018
I have noticed that these 'hats' look a whole lot like baggage on top of these people's heads, as if that is all they were able to carry with them when the lower lands flooded near the end of the last ice age, forcing the people, with only what they could carry, up the mountains that were not being flooded. And then the statues to commemorate the event and to tel future generations to Watch The Sky for Meteor and Cometary impacts. As have clearly happened before, and surely been the destruction of at least one civilization here on this planet.

You really know nothing about Easter Island culture and history, do you?

Jun 04, 2018
Oh, that reminds me. guy wrote a short story that included our studly engineer type living alone in an isolated house deep in the woods during a heavy winter blizzard.

After the weather cleared, he had to go up onto his roof to sweep the snow off the solar panels that powered his technological man-cave.

Being an engineer and despite that handicap, having uncommon good sense. He had prepared a method to safely get up on his roof and better yet, safely return to the ground. Using an assortment of pulleys, ropes and harness.

He tried to explain his method in meticulous detail to people. Many of them, their eyes glazed over and they tuned out his explanation of how a pulley system works.

When he noticed his audience tuning him out? In the same dull drone he would end with. "Then the fairies magically lift me down."

As they nodded, satisfied with that answer, he would think to himself "Twits!"

Jun 05, 2018
The South Pacific is filled with native stories that the lands they lived on were flooded, and that they live on the mountain tops of what was before. We have found that the sea level, around the world, rose by at least two hundred to four hundred feet. It has given a lot of weight to those stories when the geologists start backing up the dates etc. The South Pacific Islanders have a very detailed history that fits with what modern science has been able to determine. There is no reason to not apply this to Easter Island.

As far as what civilization, tell me who did the massive stone works such as the pyramids at Giza, the Pre-Mayan walls, places like Pumu Punku and the like, where there is ample evidence of tech AT LEAST Our Level doing stonework our best now shudder at. And it is laying in tumbled ruin now, worldwide. SO, There HAD to have been a high tech culture before this one, that we have found bits of as we hare refound civilization along the way. But, They pre-date us.

Jun 05, 2018
Damn it! I hate to admit that an engineer, even a fictional one, could be correct. But, yeah "Twits!".

Sw, since you are admitting that you are incompetent to build anything more complicated than a (small) Lego kit?

You do realize that makes you incompetent to judge even the most primitive of peoples capacity for engineering genius.

To quote "I am not a genius. I just build on other peoples ideas. The ancient Australian native who invented and developed the boomerang was a true genius!"

Jun 06, 2018
As a Navy Welder, then Fabricator, Sword and Armorsmith running my own business and then Draftsman/Engineer training, I would not say I am incompetent. Heck, I could have run a multi-block set of pulleys and done the labor part easy, just takes a lot of elbow grease to pull rope. And yes, I know my rope too, was splicing it at 5 as dad was a sailor and taught me proper. I actually come from the old days when we really learned things not just in school, not just at home, but also by living life to the fullest. You find great glee at putting people down because you think you are both smarter than they are and can do more than they, and in both cases you keep running into this stumbling block that there are people out here smarter than you are, that can do more than you, that HAS done more than you. In my 20s I was running asbestos removals in high radiation spaces shortly after shutdown.

So do not Even go there!

Jun 06, 2018
Sw, you claim to have an engineering background, training and experience. I have no way to dispute that claim.

Yet you are willing to repeat fairytales without a shred of supporting evidence.

Those "native' stories you fancy? Have for centuries been exposed to contamination from sailor's tall tales. And especially corrupted by missionaries who had their own sets of fairytales to expound upon.

All blending together into an incoherent mishmash. No matter that you wish to believe those stories to be original truth.

Whatever emotional validation you gain out being gullible? You need to reach back into your education. Back to the scientific principles that were taught you. And apply those tools of reason to this narrative.

Jun 07, 2018
I do not repeat 'fairytales', I point out solid items and ask How did they do that before the last ice age, which is how old the items are. Many of the statues at Rapa Nui are only from the waist up, with less or rougher detail. They are obviously newer construction based on the Really Old Ones. The Older ones happen to be full height depictions of people, but they are buried in mud and silts up to chest level, and are intricately carved.

Take a look at the stonework at Pumapunka, (again, pre-last ice age) and tell me that it did not take some sort of high tech to do the work., Baalbek, Giza etc.

Archeology has been coming to terms that major floods have happened, for a variety of reasons, melting ice caps from an ice age has the ruins of the Last Big Civilizations covered under 2-400 ft of water. This is from the Archaeologists, not merely personal fancy.

Perhaps studying outside of your small box will do you some good, allow you to see where some of these points meet up

Jun 08, 2018
I do not repeat 'fairytales'
Willis dont repeat fareytales, he make up his own.

Jun 08, 2018
I may be mistaken, but I believe this is the very same mechanism proposed by Thor Heyerdahl based on interviews with local people.

Steelwolf, if you **actually** look at the stonework at Puma Punqa, Sacsayhuaman, Ollantaytambo, etc. you can see that the technologies used are exactly those recorded by the Spanish barbarians and the Andean chroniclers. They hit rocks with harder rocks until they were the right shape, dragged them to the site, and using other rocks, levers and ropes finished them onsite. The "peck marks" (that's what they're really called) of the stone tools used are still clearly visible on stones with unfinished faces and on the back side of the finished ones. At sites that were still under construction when the European-introduced diseases destroyed the population, such as Ollantaytambo, you can very clearly see the different stages of the process as work was abandoned.

Jun 10, 2018
Actually the Andeans will clearly tell you that the big stones were there before they got there. They are NOT just 'pecked out rocks' like you seem to think, they were precisely machined, with clean 90 degree inner and outer corners, sharp 3/8 inch wide and deep cuts with 3/8 inch holes drilled at approximately every 2 inches, but exactly regularly spaced, and all tolerances on the rock are STILL to within 10/1000ths of an inch. So, no, it is not just pecked out stonework, take a close look at the matching H-Block construction, found essentially as they would have been tumbled as if from ice-age, flooding and time.

Take a look at the fieldwork done, even on YouTube, exploring these places, and the degree of tech required to do the stonework is beyond what the Andean Cultures we know of ever had. Modern Archaeology has come a long way beyond discounting things of superior workmanship and technological province as 'Uhh, I Dunno' and hide it in the back of the museum as 'Unknown'

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