The Kyrenia shipwreck has a new estimate for the year it sank, study says

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A lone diver first spotted the ancient Kyrenia shipwreck off the northern coast of Cyprus nearly 60 years ago. But when archaeologists tried to determine the exact timeline of the vessel that came to rest on the ocean floor, they had no choice but to speculate based on the ship’s cargo.

Now, a new study published Wednesday in the journal PLOS One may have a better time estimate for Kyrenia’s demise — and the revelation comes thanks to newly cleaned wood samples from the ship, as well as clues provided by a twig, an animal bone. and a stash of old almonds.

Local diver Andreas Cariolou first discovered the Kyrenia in 1965, one of the first large Greek ships from the Hellenistic period to be found largely intact, and a team led by the late marine archaeologist Michael Katzev excavated the wreck and its cargo in the late 1960s.

Scientists originally believed the vessel sank around 300 BC. One text, the first volume of the site’s final reports published in 2022, he estimated a range of 294 BC to 290 BC, based on pottery and some coins found on board. However, according to the latest study, no scientific dating was available to support these estimates.

Using radiocarbon dating – a method used to determine the age of organic materials such as wood from trees – and dendrochronology, the science of dating tree rings, the researchers of the new study determined that the Kyrenia sinking occurred between 296 BC and 271 BC. And they found a high probability that it happened between 286 BC and 272 BC, the study authors wrote.

“We have dates that are very close to those recently proposed by archaeologists, but just a little more recent,” said lead author Sturt Manning, Distinguished Professor of the Arts and Sciences of Classical Archeology at Cornell University in New York.

While an updated timeline backed by scientific data is important to the famous ship, the key revelation is in the new techniques and revised radiocarbon calibration that can help scientists more accurately date structures and shipwrecks from the period, Manning said.

According to Manning, two main obstacles stood in the way of achieving a highly accurate estimate of the age of the Kyrenia wreck. The first was that polyethylene glycol, or PEG, a petroleum-derived compound used to preserve ship’s wood, interfered with radiocarbon dating.

Wrecks often remain well preserved due to the lack of oxygen on the ocean floor. But once the materials come to the surface, they deteriorate quickly, Manning explained. Injecting polyethylene glycol into the wood prevents the wood from being crushed and turned into a powder, but then it becomes difficult to remove over time.

“You need to have literally a fraction of a percent of this material (polyethylene glycol) in there and the date will be wrong, often by hundreds if not thousands of years,” said Manning, who has been trying to date Kyrenia. ship 10 years ago but failed due to PEG.

However, an international team of researchers developed a cleaning protocol, described in an October 2021 study, that successfully removed the petroleum-based compound from wood that had been recently preserved, Manning said. To confirm that the protocol would work with something as old as the Kyrenia shipwreck, Manning and his colleagues applied the technique to a piece of PEG-preserved wood they knew was from nearly 2,000 years ago and found the exact radiocarbon age.

Now with a solution for cleaning the wood, scientists thought they would be able to date the ship’s wood. But instead, they ran into a second hurdle and kept getting ages that didn’t match “any possible archaeological solution around,” Manning said.

Upon investigation, he and his team found that the International Northern Hemisphere Radiocarbon Calibration Curve, a conversion of measurements to dates based on known tree rings, was out of date for the period between about 400 BC and 250 BC.

The researchers were able to formulate their date estimate by recalibrating the curve using redwood and oak samples of known age from this period. The revised curve was critical to pinpointing the exact time frame for the Kyrenia shipwreck and could further help researchers around the world who face similar challenges in dating ancient structures, Manning said.

The radiocarbon age of the wood gave researchers an idea of ​​when the ship was built, but it was the cargo of almonds that gave the study authors an estimate of when the shipwreck occurred, Manning said. “If you have material like almonds—or you can imagine olives or something like that that was used as a food crop—and it was on the ship when it sank, it must have been there for about a year… or maybe two years older, than when the ship sank.”

Using organic materials from the cargo, such as almonds, an unidentified wooden twig that was not part of the ship’s construction, and the ankle of farm animals, the researchers were able to narrow down the dates and estimate the range of years when the Kyrenia’s last voyage took place.

“Part of the value of this story is about the process. … the fields of (radiocarbon) dating and dendrochronology have grown, developed and refined their results over many decades,” Mark Lawall, a professor in the Department of Classics at the University of Manitoba in Winnipeg, said in an email. “Science – whether ‘hard’ or ‘soft’ – develops over time through a great deal of work ‘in the trenches’. It takes time and it takes time.” He was not involved in the new study.

With a slight change in the estimated date of the sinking, it is impressive that the original dates based on archaeological evidence of pottery and coins were only a few years apart, said Lawall, who studied amphorae, ancient Greek vessels used to transport wine, olive oil. and other goods from the Kyrenia shipwreck.

“The other part of Kyrenia’s story is his window into past lives, which are otherwise difficult to ‘see’ through known ancient writers (or even lesser known ones),” Lawall said. “The crew of the Kyrenia may have been a group of more marginal traders, taking what they could, where and when they could, hoping for a small profit at the end of the day.

He added: “They acted across cultures and were part of an enormously complex network that linked all parts of the Mediterranean together. In this way we begin to understand the origins of the modern, multicultural and interconnected Mediterranean world.