Decades after the discovery of the famous Kyrenia shipwreck, researchers have a new estimate of when it sank

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A lone diver first saw the ancient Kyrenia shipwreck off the north coast of Cyprus almost 60 years ago. But when archaeologists tried to determine the exact timeline in which the ship came to rest on the ocean floor, they had to speculate based on the ship’s cargo.

Now, a new study published Wednesday in the journal PLOS One may have a better estimate of the time of the Kyrenia’s disappearance – and the revelation came thanks to freshly cleaned wood samples from the ship, as well as clues provided by a twig, an animal bone and a cache of old objects. almonds.

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

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

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

“We got dates very close to what archaeologists have been suggesting recently, but a little more recent,” said the study’s lead author, Sturt Manning, distinguished professor of arts and sciences in classical archeology at Cornell University in New York.

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

Dating a Hellenistic Era Ship

Two main obstacles have prevented obtaining a highly accurate age estimate for the Kyrenia wreck, according to Manning. The first was that polyethylene glycol or PEG, a petroleum-derived compound used to preserve the ship’s wood, was interfering with radiocarbon dating.

Shipwrecks often remain well preserved due to a lack of oxygen on the ocean floor. But once the materials are brought to the surface, they deteriorate quickly, Manning explained. Injecting polyethylene glycol into the wood prevents the wood from disintegrating and turning into dust, but it becomes difficult to remove over time.

“You only need to have literally a fraction of a percent of that material (polyethylene glycol) in there, and the date will be off, often by hundreds if not thousands of years,” said Manning, who tried to date the Kyrenia. launched 10 years ago but failed because of PEG.

However, an international team of researchers has developed a cleaning protocol, described in a October 2021 Study, which successfully removed the petroleum-based compound from wood that was recently pickled, 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 to be from nearly 2,000 years ago and found accurate radiocarbon ages.

Now with a solution to clean the wood, researchers thought they would be able to date the ship’s wood. But instead they hit a second obstacle and kept getting ages that didn’t match “any possible archaeological solution,” Manning said.

After investigating, he and his team determined that the international Northern Hemisphere radiocarbon calibration curve, the conversion of measurements to dates based on known tree rings, was outdated for the period between about 400 BC and 250 BC.

The researchers were able to formulate their date estimate by recalibrating the curve using samples of redwoods and oaks of known age from this period. The revised curve was critical in determining an accurate time period for the sinking of the Kyrenia and could further help researchers around the world who face similar problems in dating ancient structures, Manning said.

A treasure trove of ancient almonds

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

By using organic materials from the cargo, such as almonds, an unidentified wooden branch that was not part of the ship’s construction, and a cattle ankle bone, researchers were able to narrow down the dates and estimate a range of years for when the A Kyrenia’s last voyage took place.

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

With the slight modification in the estimated date of the sinking, it is striking that the original dates based on archaeological evidence from pottery and coins were only a few years off, said Lawall, who has studied amphorae, ancient greek containers used to transport wine, olive oil and other goods, originating from the Kyrenia shipwreck.

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

He added: “They dealt with different cultures and in doing so were part of an immensely complex network that linked all parts of the Mediterranean. In this way, we begin to understand the origins of the modern, multicultural and interconnected Mediterranean world.”

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