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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 pinpoint the exact time the ship came to rest on the ocean floor, they had to speculate based on the ship’s cargo.
A new study published Wednesday in the journal PLOS One may have a better time estimate for Kyrenia’s demise — and the discovery came together thanks to clues provided by a branch, an animal bone, as well as freshly cleaned wood samples taken from the ship. and a cache of old almonds.
Local diver Andreas Cariolou first discovered the Kyrenia ship, one of the first large Greek Hellenistic period ships 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 60s.
Researchers initially believed that the ship sank around 300 BC. Single text, first volume of the site’s final reports Published in 2022, an estimated range of 294 BC to 290 BC is based on pottery and some coins found on the ship. However, according to the latest research, there was no scientific dating to support the predictions.
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, researchers of the new study determined that the sinking of Kyrenia occurred between 296 BC and 271 BC. The study authors found this was most likely to have happened between 286 BC and 272 BC.
“We got dates that are very close to what archaeologists have recently suggested, but slightly closer,” said Sturt Manning, professor of arts and sciences in classical archeology at Cornell University in New York and lead author of the study.
Manning said that while an updated timeline for the famous ship backed by scientific data is important, the real breakthrough is new techniques and revised radiocarbon calibration that can help scientists more accurately date structures and shipwrecks from this period.
Going out on a Hellenistic ship
According to Manning, there were two main obstacles to making a high-precision age estimate for the Kyrenia shipwreck. The first was that polyethylene glycol, or PEG, a petroleum-derived compound used to preserve the ship’s wood, interfered with radiocarbon dating.
Often, shipwrecks remain well preserved due to the lack of oxygen at the bottom of the ocean. However, Manning explained that the materials quickly deteriorate once they reach the surface. Injecting polyethylene glycol into the wood prevents the wood from crumbling and becoming powdery, but it becomes difficult to remove over time.
Trying to date Kyrenia, Manning said, “All it takes is literally less than one percent of this substance (polyethylene glycol) there and the date will be off for hundreds if not thousands of years.” It was sent on board 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 preserved wood fairly recently, Manning said. To confirm that the protocol would work with something as old as the Kyrenia shipwreck, Manning and colleagues applied the technique to a PEG-preserved piece of wood that they knew to be around 2,000 years old and found accurate radiocarbon ages.
Thanks to a solution for cleaning leftover wood, researchers thought the ship’s wood could be dated. But instead they ran into a second roadblock and continued to take ages that didn’t fit “any possible archaeological solution around,” Manning said.
As a result of his research with his team, he determined that the Northern Hemisphere international radiocarbon calibration curve, obtained by converting measurements based on known tree rings into dates, was outdated for the period between 400 BC and 250 BC.
By recalibrating the curve using redwood and oak samples of known age from this period, the researchers were able to formulate date estimates. Manning said the revised curve is critical to determining an accurate time frame for the Kyrenia shipwreck and could further assist researchers around the world who face similar problems in dating ancient structures.
ancient almond treasure
Radiocarbon ages of the wood gave researchers an idea of when the ship was built, Manning said, but it was the cargo of almonds that gave the study authors a date estimate for when the shipwreck occurred. “If you have an ingredient like almonds – or olives or anything like that that’s used as a food product – and it was on the ship when it sank, it probably had to have been there for a year… or maybe it was two years before a ship sank.” .”
Using organic materials recovered from the cargo, such as almonds, an unidentified tree branch that was not part of the ship’s structure, and the ankle bone of livestock, researchers were able to narrow down the dates and estimate the range of years in which this event occurred. The last voyage of the Kyrenia ship has taken place.
“Part of the value of this story is about the process. … The fields of (radiocarbon) dating and dendrochronology have grown, evolved and improved their results over the decades,” Mark Lawall, a professor in the classics department at the University of Manitoba in Winnipeg, said in an email. “Science – whether ‘hard’ or ‘soft’ – improves over time with a lot of work done ‘in the trenches’. It takes time and it needs time.” He was not involved in the new study.
Lawall, who studies amphorae, ancient Greek containers used to transport wine and olive oil, said it was impressive that, with the slight change in estimated sinking date, the original dates based on archaeological evidence for ceramics and coins differed by only a few years. and other items from the Kyrenia shipwreck.
“The other part of the Kyrenia story is its window into past lives that are hard to ‘see’ through the well-known ancient writers (or lesser-known ones),” Lawall said. “The Kyrenia crew may have been a group of more marginal traders, taking whatever they could, wherever and whenever they wanted, hoping to make a small profit at the end of the day.”
He added: “They were trading across cultures and in doing so they were part of an extremely complex network that connected all parts of the Mediterranean. In this way we begin to understand the origins of the modern, multicultural, interconnected Mediterranean world.”
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