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Fine-Tuning Radiocarbon Dating Will Rewrite History!

Fine-Tuning Radiocarbon Dating Will Rewrite History!


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Radiocarbon dating, invented in the late 1940s and improved ever since to provide more precise measurements, is the standard method for determining the dates of artifacts in archaeology and other disciplines. But this method isn’t perfect , some fine-tuning is needed.

“If it’s organic and old – up to 50,000 years – you date it by radiocarbon,” said Sturt Manning, the Goldwin Smith Professor of Classical Archaeology in the College of Arts and Sciences.

Manning is lead author of a new paper that points out the need for an important new refinement to the technique. The outcomes of his study, published March 18 in Science Advances , have relevance for understanding key dates in Mediterranean history and prehistory, including the tomb of Tutankhamen and a controversial but important volcanic eruption on the Greek island of Santorini.

What is Radiocarbon Dating?

Radiocarbon dating measures the decomposition of carbon-14, an unstable isotope of carbon created by cosmic radiation and found in all organic matter. Cosmic radiation, however, is not constant at all times. To account for fluctuations of cosmic radiation in the Earth’s atmosphere, the radiocarbon content of known-age tree rings was measured backward in time from the 20th century, for thousands of years.

Tree-ring calibrated radiocarbon started to be widely used 50 years ago. A standard calibration curve was introduced in 1986 and is updated every few years as more data are added.

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“A single Northern Hemisphere calibration curve has formed the basis of radiocarbon dating in Europe and the Mediterranean for five decades, setting the time frame for prehistory,” Manning and co-authors write. “However, as measurement precision increases, there is mounting evidence for some small but substantive regional (partly growing season) offsets in the same-year radiocarbon levels.”

Radiocarbon Needs Refining

In their study, Manning and co-authors question the accuracy of a single calibration curve for all of the Northern Hemisphere. Using data collected by only one lab to control for interlaboratory variation, they compared radiocarbon data from northern Europe (Germany) and from the Mediterranean (central Turkey) in the 2nd and 1st millennia BC. They found that some small but critical periods of variation for Mediterranean radiocarbon levels exist. Data from two other radiocarbon labs on samples from central Italy and northern Turkey then provided consistency.

Growing seasons play a role, the paper says. The radiocarbon level on Earth varies according to the season; there’s a winter low and a summer high, Manning said. The carbon in a tree ring reflects when the tree was photosynthesizing and, therefore, taking carbon out of the atmosphere.

The carbon in a tree ring reflects when the tree was photosynthesizing and, therefore, taking carbon out of the atmosphere. ( Pixabay License )

“In northern Europe or in North America, a tree is going to be doing this in April through September. But a tree in Jordan or Israel does that October through April – almost the opposite time of the year,” he said.

In 2018, Manning noted “scholars working on the early Iron Age and Biblical chronology in Jordan and Israel are doing sophisticated projects with radiocarbon age analysis, which argue for very precise findings. This then becomes the timeline of history. But our work indicates that it's arguable their fundamental basis is faulty -- they are using a calibration curve that is not accurate for this region.”

Sturt Manning cores a multi-century old Juniperus phoenicea tree near Petra in southern Jordan. ( Cornell University )

These variations, although small, potentially affect calendar dates for prehistory by up to a few decades, the paper concludes.

Special Significance for Dating Key Historical Moments

Even small date offsets – 50 years or less – are important for building the timeline of the Mediterranean region, which, in the last two millennia BC, was a hotbed of interrelated cultures.

The adjusted dates confirm previously awkward timelines, where radiocarbon and history did not seem to agree for some historical landmarks, including the death and burial of Egyptian pharaoh Tutankhamen , which is dated around the 1320s to 1310s BC, according to recent Egyptology.

Howard Carter and associates opening the shrine doors in the burial chamber of Tutankhamen’s tomb.

The study also addresses a debate over the date of a massive volcanic eruption on Santorini. This much-studied event is dated around 1500 BC by archaeologists but earlier – 1630 to 1600 BC – by scientists. Manning said the new findings rule out the date of 1500 BC, but may also modify the science.

A 1630–1600 BC date remains possible, but a later date in the range of 1600-1550 BC now becomes plausible, and even works better with existing archaeological and historical records, including writings from Egypt.

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Hypothetical calendar dating probability estimates for the Santorini/Thera volcanic destruction level from the study’s data and models. ( Manning et al. 2020 )

The study also has ramifications for understanding which culture influenced the Minoans and Mycenaeans, which led to ancient Greece.

“Getting the date right will rewrite and get our history correct in terms of what groups were significant in shaping what then became classical civilization,” Manning said. “An accurate timeline is key to our history.”

He predicts follow-up on this study and a future with more specific regional calibration curves within the Northern Hemisphere – as well as subsequent adjustment to historical dates.


Fine-tuning radiocarbon dating could 'rewrite' ancient events

ITHACA, N.Y. - Radiocarbon dating, invented in the late 1940s and improved ever since to provide more precise measurements, is the standard method for determining the dates of artifacts in archaeology and other disciplines.

"If it's organic and old - up to 50,000 years - you date it by radiocarbon," said Sturt Manning, the Goldwin Smith Professor of Classical Archaeology in the College of Arts and Sciences.

Manning is lead author of a new paper that points out the need for an important new refinement to the technique. The outcomes of his study, published March 18 in Science Advances, have relevance for understanding key dates in Mediterranean history and prehistory, including the tomb of Tutankhamen and a controversial but important volcanic eruption on the Greek island of Santorini.

Radiocarbon dating measures the decomposition of carbon-14, an unstable isotope of carbon created by cosmic radiation and found in all organic matter. Cosmic radiation, however, is not constant at all times. To account for fluctuations of cosmic radiation in the Earth's atmosphere, the radiocarbon content of known-age tree rings was measured backward in time from the 20th century, for thousands of years.

Tree-ring calibrated radiocarbon started to be widely used 50 years ago. A standard calibration curve was introduced in 1986 and is updated every few years as more data are added.

"A single Northern Hemisphere calibration curve has formed the basis of radiocarbon dating in Europe and the Mediterranean for five decades, setting the time frame for prehistory," Manning and co-authors write. "However, as measurement precision increases, there is mounting evidence for some small but substantive regional (partly growing season) offsets in the same-year radiocarbon levels."

In their study, Manning and co-authors question the accuracy of a single calibration curve for all of the Northern Hemisphere. Using data collected by only one lab to control for interlaboratory variation, they compared radiocarbon data from northern Europe (Germany) and from the Mediterranean (central Turkey) in the 2nd and 1st millennia B.C. They found that some small but critical periods of variation for Mediterranean radiocarbon levels exist. Data from two other radiocarbon labs on samples from central Italy and northern Turkey then provided consistency.

Growing seasons play a role, the paper says. The radiocarbon level on Earth varies according to the season there's a winter low and a summer high, Manning said. The carbon in a tree ring reflects when the tree was photosynthesizing and, therefore, taking carbon out of the atmosphere.

"In northern Europe or in North America, a tree is going to be doing this in April through September. But a tree in Jordan or Israel does that October through April - almost the opposite time of the year," he said.

These variations, although small, potentially affect calendar dates for prehistory by up to a few decades, the paper concludes.

Even small date offsets - 50 years or less - are important for building the timeline of the Mediterranean region, which, in the last two millennia B.C., was a hotbed of interrelated cultures.

The adjusted dates confirm previously awkward timelines, where radiocarbon and history did not seem to agree for some historical landmarks, including the death and burial of Egyptian pharaoh Tutankhamen, which is dated around the 1320s to 1310s B.C., according to recent Egyptology.

The study also addresses a debate over the date of a massive volcanic eruption on Santorini. This much-studied event is dated around 1500 B.C. by archaeologists but earlier - 1630 to 1600 B.C. - by scientists. Manning said the new findings rule out the date of 1500 B.C., but may also modify the science. A 1630-1600 B.C. date remains possible, but a later date in the range 1600-1550 B.C. now becomes plausible, and even works better with existing archaeological and historical records, including writings from Egypt.

The study also has ramifications for understanding which culture influenced the Minoans and Mycenaeans, which led to ancient Greece.

"Getting the date right will rewrite and get our history correct in terms of what groups were significant in shaping what then became classical civilization," Manning said. "An accurate timeline is key to our history."

He predicts follow-up on this study and a future with more specific regional calibration curves within the Northern Hemisphere - as well as subsequent adjustment to historical dates.

This research was funded in part by grants from the National Science Foundation and the Social Science and Humanities Research Council, Canada.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.


Tree-rings record intense cosmic radiation burst in 775 AD

Just over 1,200 years ago, the planet was hit by an extremely intense burst of high-energy radiation of unknown cause, scientists studying tree-ring data have found.

The radiation burst, which seems to have hit between AD 774 and AD 775, was detected by looking at the amounts of the radioactive isotope carbon-14 in tree rings that formed during the AD 775 growing season in the Northern Hemisphere. The increase in 14C levels is so clear that the scientists, led by Fusa Miyake, (pic.) a cosmic-ray physicist from Nagoya Universityin Japan, conclude that the atmospheric level of 14C must have jumped by 1.2% over the course of no longer than a year, about 20 times more than the normal rate of variation. Their study is published online in Nature.

"The work looks pretty solid," says Daniel Baker, a space physicist at the University of Colorado's Laboratory for Atmospheric and Space Physics in Boulder, Colorado. "Some very energetic event occurred in about AD 775."

Exactly what that event was, however, is more difficult to determine.

The 14C isotope is formed when highly energetic radiation from outer space hits atoms in the upper atmosphere, producing neutrons. These collide with nitrogen-14, which then decays to 14C. (The fact that this is always happening because of background radiation is what produces a continuous source of 14C for radiocarbon dating.)

Cosmic puzzle

The only known events that can produce a 14C spike are floods of γ-rays from supernova explosions or proton storms from giant solar flares. But neither seems likely, Miyake says, because each should have been large enough to have had other effects that would have been observed at the time.

A massive supernova, for example, should have been bright enough to produce a 'new' star visible even in the daytime, as was the case for two known supernovae in AD 1006 and AD 1054. Such an explosion would have needed to be brighter than either of these, Miyake says, because those events were not large enough to leave traces in the 14C record.

It is possible, she says, that the proposed event might have occurred in the far southern skies, where astronomers of the era wouldn't have seen it. But still, she says, if it did happen, today's X-ray and radio astronomers should have found signs of a "tremendously bright" remnant of the explosion.

As for solar flares, she says, anything that could have produced the required amount of super-high-energy protons would have vastly exceeded the most intense solar outburst ever recorded. There should have been a historical record of extraordinary auroras — not to mention that such a gigantic flare would probably have destroyed the ozone layer, with devastating ecological consequences.

Baker, however, thinks that Miyake's team may have been too quick to rule out a solar flare. Flares are sometimes associated with coronal mass ejections (CMEs) — huge eruptions of magnetically charged plasma from the Sun's atmosphere that send streams of charged particles towards Earth. It might be possible, he says, for CMEs to be accompanied by conditions in which an unusual number of protons are accelerated to super-high energies, even without the flare itself being "ridiculously strong".

"We know much more these days about how important proton acceleration is at the shock fronts that precede CME structures as they propagate towards Earth," Baker says. "I would like to think about whether a strong CME moving directly towards Earth could have produced the intense proton population that impacted Earth's atmosphere."

"It would be fascinating," Baker adds, "if there were some record in China or in the Middle East that reported powerful aurora or some other such event" around the same time as the observed 14C increase.


Fine-Tuning Radiocarbon Dating Will Rewrite History! - History

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Tree rings (stock image).Credit: © CrispyMedia / Adobe Stock

Radiocarbon dating, invented in the late 1940s and improved ever since to provide more precise measurements, is the standard method for determining the dates of artifacts in archaeology and other disciplines.

“If it’s organic and old — up to 50,000 years — you date it by radiocarbon,” said Sturt Manning, the Goldwin Smith Professor of Classical Archaeology in the College of Arts and Sciences.

Manning is lead author of a new paper that points out the need for an important new refinement to the technique. The outcomes of his study, published March 18 in Science Advances, have relevance for understanding key dates in Mediterranean history and prehistory, including the tomb of Tutankhamen and a controversial but important volcanic eruption on the Greek island of Santorini.

Radiocarbon dating measures the decomposition of carbon-14, an unstable isotope of carbon created by cosmic radiation and found in all organic matter. Cosmic radiation, however, is not constant at all times. To account for fluctuations of cosmic radiation in the Earth’s atmosphere, the radiocarbon content of known-age tree rings was measured backward in time from the 20th century, for thousands of years.

Tree-ring calibrated radiocarbon started to be widely used 50 years ago. A standard calibration curve was introduced in 1986 and is updated every few years as more data are added.

“A single Northern Hemisphere calibration curve has formed the basis of radiocarbon dating in Europe and the Mediterranean for five decades, setting the time frame for prehistory,” Manning and co-authors write. “However, as measurement precision increases, there is mounting evidence for some small but substantive regional (partly growing season) offsets in the same-year radiocarbon levels.”

In their study, Manning and co-authors question the accuracy of a single calibration curve for all of the Northern Hemisphere. Using data collected by only one lab to control for interlaboratory variation, they compared radiocarbon data from northern Europe (Germany) and from the Mediterranean (central Turkey) in the 2nd and 1st millennia B.C. They found that some small but critical periods of variation for Mediterranean radiocarbon levels exist. Data from two other radiocarbon labs on samples from central Italy and northern Turkey then provided consistency.

Growing seasons play a role, the paper says. The radiocarbon level on Earth varies according to the season there’s a winter low and a summer high, Manning said. The carbon in a tree ring reflects when the tree was photosynthesizing and, therefore, taking carbon out of the atmosphere.

“In northern Europe or in North America, a tree is going to be doing this in April through September. But a tree in Jordan or Israel does that October through April — almost the opposite time of the year,” he said.

These variations, although small, potentially affect calendar dates for prehistory by up to a few decades, the paper concludes.

Even small date offsets — 50 years or less — are important for building the timeline of the Mediterranean region, which, in the last two millennia B.C., was a hotbed of interrelated cultures.

The adjusted dates confirm previously awkward timelines, where radiocarbon and history did not seem to agree for some historical landmarks, including the death and burial of Egyptian pharaoh Tutankhamen, which is dated around the 1320s to 1310s B.C., according to recent Egyptology.

The study also addresses a debate over the date of a massive volcanic eruption on Santorini. This much-studied event is dated around 1500 B.C. by archaeologists but earlier — 1630 to 1600 B.C. — by scientists. Manning said the new findings rule out the date of 1500 B.C., but may also modify the science. A 1630-1600 B.C. date remains possible, but a later date in the range 1600-1550 B.C. now becomes plausible, and even works better with existing archaeological and historical records, including writings from Egypt.

The study also has ramifications for understanding which culture influenced the Minoans and Mycenaeans, which led to ancient Greece.

“Getting the date right will rewrite and get our history correct in terms of what groups were significant in shaping what then became classical civilization,” Manning said. “An accurate timeline is key to our history.”

He predicts follow-up on this study and a future with more specific regional calibration curves within the Northern Hemisphere — as well as subsequent adjustment to historical dates.

This research was funded in part by grants from the National Science Foundation and the Social Science and Humanities Research Council, Canada.

Story Source:

Materials provided by Cornell University. Original written by Kate Blackwood. Note: Content may be edited for style and length.

Journal Reference:

  1. Sturt W. Manning, Bernd Kromer, Mauro Cremaschi, Michael W. Dee, Ronny Friedrich, Carol Griggs, Carla S. Hadden. Mediterranean radiocarbon offsets and calendar dates for prehistory. Science Advances, 2020 6 (12): eaaz1096 DOI: 10.1126/sciadv.aaz1096.
Posted in General Tags: Fine-tuning radiocarbon dating, Riffin T Sajeev, Russel T Sajeev, WFS, WFS NEWS, world fossil society

Fine-tuning radiocarbon dating could ‘rewrite’ ancient events

Radiocarbon dating, invented in the late 1940s and improved ever since to provide more precise measurements, is the standard method for determining the dates of artifacts in archaeology and other disciplines.

“If it’s organic and old – up to 50,000 years – you date it by radiocarbon,” said Sturt Manning, the Goldwin Smith Professor of Classical Archaeology in the College of Arts and Sciences.

Manning is lead author of a new paper that points out the need for an important new refinement to the technique. The outcomes of his study, published March 18 in Science Advances, have relevance for understanding key dates in Mediterranean history and prehistory, including the tomb of Tutankhamen and a controversial but important volcanic eruption on the Greek island of Santorini.

Radiocarbon dating measures the decomposition of carbon-14, an unstable isotope of carbon created by cosmic radiation and found in all organic matter. Cosmic radiation, however, is not constant at all times. To account for fluctuations of cosmic radiation in the Earth’s atmosphere, the radiocarbon content of known-age tree rings was measured backward in time from the 20th century, for thousands of years.

Tree-ring calibrated radiocarbon started to be widely used 50 years ago. A standard calibration curve was introduced in 1986 and is updated every few years as more data are added.

“A single Northern Hemisphere calibration curve has formed the basis of radiocarbon dating in Europe and the Mediterranean for five decades, setting the time frame for prehistory,” Manning and co-authors write. “However, as measurement precision increases, there is mounting evidence for some small but substantive regional (partly growing season) offsets in the same-year radiocarbon levels.”

A juniper tree section from Jordan in the Southern Levant. Photo by Sturt Manning

In their study, Manning and co-authors question the accuracy of a single calibration curve for all of the Northern Hemisphere. Using data collected by only one lab to control for interlaboratory variation, they compared radiocarbon data from northern Europe (Germany) and from the Mediterranean (central Turkey) in the 2nd and 1st millennia B.C. They found that some small but critical periods of variation for Mediterranean radiocarbon levels exist. Data from two other radiocarbon labs on samples from central Italy and northern Turkey then provided consistency.

Growing seasons play a role, the paper says. The radiocarbon level on Earth varies according to the season there’s a winter low and a summer high, Manning said. The carbon in a tree ring reflects when the tree was photosynthesizing and, therefore, taking carbon out of the atmosphere.

“In northern Europe or in North America, a tree is going to be doing this in April through September. But a tree in Jordan or Israel does that October through April – almost the opposite time of the year,” he said.

These variations, although small, potentially affect calendar dates for prehistory by up to a few decades, the paper concludes.

Even small date offsets – 50 years or less – are important for building the timeline of the Mediterranean region, which, in the last two millennia B.C., was a hotbed of interrelated cultures.

The adjusted dates confirm previously awkward timelines, where radiocarbon and history did not seem to agree for some historical landmarks, including the death and burial of Egyptian pharaoh Tutankhamen, which is dated around the 1320s to 1310s B.C., according to recent Egyptology.

The study also addresses a debate over the date of a massive volcanic eruption on Santorini. This much-studied event is dated around 1500 B.C. by archaeologists but earlier – 1630 to 1600 B.C. – by scientists. Manning said the new findings rule out the date of 1500 B.C., but may also modify the science. A 1630–1600 B.C. date remains possible, but a later date in the range 1600-1550 B.C. now becomes plausible, and even works better with existing archaeological and historical records, including writings from Egypt.

The study also has ramifications for understanding which culture influenced the Minoans and Mycenaeans, which led to ancient Greece.

“Getting the date right will rewrite and get our history correct in terms of what groups were significant in shaping what then became classical civilization,” Manning said. “An accurate timeline is key to our history.”

He predicts follow-up on this study and a future with more specific regional calibration curves within the Northern Hemisphere – as well as subsequent adjustment to historical dates.

This research was funded in part by grants from the National Science Foundation and the Social Science and Humanities Research Council, Canada.


Radiocarbon dating, invented in the late 1940s and improved ever since to provide more precise measurements, is the standard method for determining the dates of artifacts in archaeology and other disciplines.

“If it’s organic and old – up to 50,000 years – you date it by radiocarbon,” said Sturt Manning, the Goldwin Smith Professor of Classical Archaeology in the College of Arts and Sciences.

Manning is lead author of a new paper that points out the need for an important new refinement to the technique. The outcomes of his study, published March 18 in Science Advances, have relevance for understanding key dates in Mediterranean history and prehistory, including the tomb of Tutankhamen and a controversial but important volcanic eruption on the Greek island of Santorini.

Radiocarbon dating measures the decomposition of carbon-14, an unstable isotope of carbon created by cosmic radiation and found in all organic matter. Cosmic radiation, however, is not constant at all times. To account for fluctuations of cosmic radiation in the Earth’s atmosphere, the radiocarbon content of known-age tree rings was measured backward in time from the 20th century, for thousands of years.

Tree-ring calibrated radiocarbon started to be widely used 50 years ago. A standard calibration curve was introduced in 1986 and is updated every few years as more data are added. Manning and co-authors write:

In their study, Manning and co-authors question the accuracy of a single calibration curve for all of the Northern Hemisphere. Using data collected by only one lab to control for interlaboratory variation, they compared radiocarbon data from northern Europe (Germany) and from the Mediterranean (central Turkey) in the 2nd and 1st millennia BC. They found that some small but critical periods of variation for Mediterranean radiocarbon levels exist. Data from two other radiocarbon labs on samples from central Italy and northern Turkey then provided consistency.

Growing seasons play a role, the paper says. The radiocarbon level on Earth varies according to the season there’s a winter low and a summer high, Manning said. The carbon in a tree ring reflects when the tree was photosynthesizing and, therefore, taking carbon out of the atmosphere.

“In northern Europe or in North America, a tree is going to be doing this in April through September. But a tree in Jordan or Israel does that October through April – almost the opposite time of the year.”

These variations, although small, potentially affect calendar dates for prehistory by up to a few decades, the paper concludes. Even small date offsets – 50 years or less – are important for building the timeline of the Mediterranean region, which, in the last two millennia B.C., was a hotbed of interrelated cultures.

The adjusted dates confirm previously awkward timelines, where radiocarbon and history did not seem to agree for some historical landmarks, including the death and burial of Egyptian pharaoh Tutankhamen, which is dated around the 1320s to 1310s BC, according to recent Egyptology.

The study also addresses a debate over the date of a massive volcanic eruption on Santorini. This much-studied event is dated around 1500 BC by archaeologists but earlier – 1630 to 1600 BC – by scientists. Manning said the new findings rule out the date of 1500 BC, but may also modify the science. A 1630-1600 B.C. date remains possible, but a later date in the range 1600-1550 BC now becomes plausible, and even works better with existing archaeological and historical records, including writings from Egypt.

The study also has ramifications for understanding which culture influenced the Minoans and Mycenaeans, which led to ancient Greece.


Fine-tuning radiocarbon dating could ‘rewrite’ ancient events

Radiocarbon dating, invented in the late 1940s and improved ever since to provide more precise measurements, is the standard method for determining the dates of artifacts in archaeology and other disciplines.

“If it’s organic and old – up to 50,000 years – you date it by radiocarbon,” said Sturt Manning, the Goldwin Smith Professor of Classical Archaeology in the College of Arts and Sciences.

Manning is lead author of a new paper that points out the need for an important new refinement to the technique. The outcomes of his study, published March 18 in Science Advances, have relevance for understanding key dates in Mediterranean history and prehistory, including the tomb of Tutankhamen and a controversial but important volcanic eruption on the Greek island of Santorini.

Radiocarbon dating measures the decomposition of carbon-14, an unstable isotope of carbon created by cosmic radiation and found in all organic matter. Cosmic radiation, however, is not constant at all times. To account for fluctuations of cosmic radiation in the Earth’s atmosphere, the radiocarbon content of known-age tree rings was measured backward in time from the 20th century, for thousands of years.

Tree-ring calibrated radiocarbon started to be widely used 50 years ago. A standard calibration curve was introduced in 1986 and is updated every few years as more data are added.

“A single Northern Hemisphere calibration curve has formed the basis of radiocarbon dating in Europe and the Mediterranean for five decades, setting the time frame for prehistory,” Manning and co-authors write. “However, as measurement precision increases, there is mounting evidence for some small but substantive regional (partly growing season) offsets in the same-year radiocarbon levels.”

A juniper tree section from Jordan in the Southern Levant. P hoto by Sturt Manning

In their study, Manning and co-authors question the accuracy of a single calibration curve for all of the Northern Hemisphere. Using data collected by only one lab to control for interlaboratory variation, they compared radiocarbon data from northern Europe (Germany) and from the Mediterranean (central Turkey) in the 2nd and 1st millennia B.C. They found that some small but critical periods of variation for Mediterranean radiocarbon levels exist. Data from two other radiocarbon labs on samples from central Italy and northern Turkey then provided consistency.

Growing seasons play a role, the paper says. The radiocarbon level on Earth varies according to the season there’s a winter low and a summer high, Manning said. The carbon in a tree ring reflects when the tree was photosynthesizing and, therefore, taking carbon out of the atmosphere.

“In northern Europe or in North America, a tree is going to be doing this in April through September. But a tree in Jordan or Israel does that October through April – almost the opposite time of the year,” he said.

These variations, although small, potentially affect calendar dates for prehistory by up to a few decades, the paper concludes.

Even small date offsets – 50 years or less – are important for building the timeline of the Mediterranean region, which, in the last two millennia B.C., was a hotbed of interrelated cultures.

The adjusted dates confirm previously awkward timelines, where radiocarbon and history did not seem to agree for some historical landmarks, including the death and burial of Egyptian pharaoh Tutankhamen, which is dated around the 1320s to 1310s B.C., according to recent Egyptology.

The study also addresses a debate over the date of a massive volcanic eruption on Santorini. This much-studied event is dated around 1500 B.C. by archaeologists but earlier – 1630 to 1600 B.C. – by scientists. Manning said the new findings rule out the date of 1500 B.C., but may also modify the science. A 1630–1600 B.C. date remains possible, but a later date in the range 1600-1550 B.C. now becomes plausible, and even works better with existing archaeological and historical records, including writings from Egypt.

The study also has ramifications for understanding which culture influenced the Minoans and Mycenaeans, which led to ancient Greece.

“Getting the date right will rewrite and get our history correct in terms of what groups were significant in shaping what then became classical civilization,” Manning said. “An accurate timeline is key to our history.”

He predicts follow-up on this study and a future with more specific regional calibration curves within the Northern Hemisphere – as well as subsequent adjustment to historical dates.

This research was funded in part by grants from the National Science Foundation and the Social Science and Humanities Research Council, Canada.


Fine-tuning radiocarbon dating could ‘rewrite’ ancient events

Radiocarbon dating, invented in the late 1940s and improved ever since to provide more precise measurements, is the standard method for determining the dates of artifacts in archaeology and other disciplines.

“If it’s organic and old — up to 50,000 years — you date it by radiocarbon,” said Sturt Manning, the Goldwin Smith Professor of Classical Archaeology in the College of Arts and Sciences.

Manning is lead author of a new paper that points out the need for an important new refinement to the technique. The outcomes of his study, published March 18 in Science Advances, have relevance for understanding key dates in Mediterranean history and prehistory, including the tomb of Tutankhamen and a controversial but important volcanic eruption on the Greek island of Santorini.

Radiocarbon dating measures the decomposition of carbon-14, an unstable isotope of carbon created by cosmic radiation and found in all organic matter. Cosmic radiation, however, is not constant at all times. To account for fluctuations of cosmic radiation in the Earth’s atmosphere, the radiocarbon content of known-age tree rings was measured backward in time from the 20th century, for thousands of years.

Tree-ring calibrated radiocarbon started to be widely used 50 years ago. A standard calibration curve was introduced in 1986 and is updated every few years as more data are added.

“A single Northern Hemisphere calibration curve has formed the basis of radiocarbon dating in Europe and the Mediterranean for five decades, setting the time frame for prehistory,” Manning and co-authors write. “However, as measurement precision increases, there is mounting evidence for some small but substantive regional (partly growing season) offsets in the same-year radiocarbon levels.”

In their study, Manning and co-authors question the accuracy of a single calibration curve for all of the Northern Hemisphere. Using data collected by only one lab to control for interlaboratory variation, they compared radiocarbon data from northern Europe (Germany) and from the Mediterranean (central Turkey) in the 2nd and 1st millennia B.C. They found that some small but critical periods of variation for Mediterranean radiocarbon levels exist. Data from two other radiocarbon labs on samples from central Italy and northern Turkey then provided consistency.

Growing seasons play a role, the paper says. The radiocarbon level on Earth varies according to the season there’s a winter low and a summer high, Manning said. The carbon in a tree ring reflects when the tree was photosynthesizing and, therefore, taking carbon out of the atmosphere.

“In northern Europe or in North America, a tree is going to be doing this in April through September. But a tree in Jordan or Israel does that October through April — almost the opposite time of the year,” he said.

These variations, although small, potentially affect calendar dates for prehistory by up to a few decades, the paper concludes.

Even small date offsets — 50 years or less — are important for building the timeline of the Mediterranean region, which, in the last two millennia B.C., was a hotbed of interrelated cultures.

The adjusted dates confirm previously awkward timelines, where radiocarbon and history did not seem to agree for some historical landmarks, including the death and burial of Egyptian pharaoh Tutankhamen, which is dated around the 1320s to 1310s B.C., according to recent Egyptology.

The study also addresses a debate over the date of a massive volcanic eruption on Santorini. This much-studied event is dated around 1500 B.C. by archaeologists but earlier — 1630 to 1600 B.C. — by scientists. Manning said the new findings rule out the date of 1500 B.C., but may also modify the science. A 1630-1600 B.C. date remains possible, but a later date in the range 1600-1550 B.C. now becomes plausible, and even works better with existing archaeological and historical records, including writings from Egypt.

The study also has ramifications for understanding which culture influenced the Minoans and Mycenaeans, which led to ancient Greece.

“Getting the date right will rewrite and get our history correct in terms of what groups were significant in shaping what then became classical civilization,” Manning said. “An accurate timeline is key to our history.”

He predicts follow-up on this study and a future with more specific regional calibration curves within the Northern Hemisphere — as well as subsequent adjustment to historical dates.

This research was funded in part by grants from the National Science Foundation and the Social Science and Humanities Research Council, Canada.


Fine-Tuning Radiocarbon Dating Will Rewrite History!

“A single Northern Hemisphere calibration curve has formed the basis of radiocarbon dating in Europe and the Mediterranean for five decades, setting the time frame for prehistory,” Manning and co-authors write. “However, as measurement precision increases, there is mounting evidence for some small but substantive regional (partly growing season) offsets in the same-year radiocarbon levels.”

A recent study suggests that the current basis for radiocarbon dating in the Middle East may be relying on an erroneous calibration based on sources outside of the Middle East. This site also reports on the study and includes a video on radiocarbon dating.


Revised tree ring data confirms ancient Mediterranean dates

Sturt Manning is leading investigations into the timelines of ancient events, using tree ring data to refine the widely used radiocarbon dating method.

In research published Aug. 17 in Scientific Reports, Manning, the Goldwin Smith Professor of Classical Archaeology in the College of Arts and Sciences, fine-tunes date ranges for ancient events in Mesopotamia, Egypt and Anatolia, and a controversial volcanic eruption on ancient Thera. He and collaborators, including Brita Lorentzen, research associate in the Cornell Tree Ring Laboratory, used IntCal20, an international calibration curve released this year, in search of higher-resolution historical chronologies.

Radiocarbon dating measures the decomposition of carbon-14, an unstable isotope of carbon found in all organic matter and created by cosmic radiation. Because cosmic radiation is not constant at all times, a database of known-age tree rings helps archaeologists calibrate radiocarbon readings against a second standard for dating objects. A standard calibration curve based on tree ring data was introduced in 1986 it is updated every few years as more data is added.

IntCal20 contains twice as much data as the previous curve, from 2013, using crowdsourced tree ring data from all over the world. Nevertheless, problems remain, Manning said, largely based on the fact that IntCal20 encompasses the entire Northern Hemisphere, which has many different growing seasons.

As demonstrated by this and previous papers from the Cornell Tree Ring Lab, problematic offsets occur in the data from different regions, depending on climate and elevation of various trees within the Northern Hemisphere. An oak growing near sea level in southwestern California grows from October to April, whereas a bristlecone pine growing in the White Mountains in eastern California grows from mid-June to early August.

These variations lead to small differences in radiocarbon levels. Applied in the east Mediterranean several thousand years ago, this could move dates by as much as 50 calendar years – changing history.

“While small,” Manning said, “these differences could be vital to high-resolution chronology in the history-rich east Mediterranean.”

Investigating ancient Mesopotamia, the team compared IntCal20 against their independent analysis of tree ring data related to the Old Assyrian/Old Babylonian period in the Bronze Age. While IntCal20 data proved incomplete, the researchers’ analysis aligns closely with textual evidence related to the reign of Shamshi-Adad I.

“This gives us a pretty secure and precise date for this king and thence the Old Assyrian and Old Babylonian periods,” Manning said. “We have substantially refined and reinforced previous work from 2016 and, in principle, this finding largely resolves many decades of scholarly debate.”

Similar investigations into Egypt confirmed existing timelines for the New Kingdom, which is related to another site and event: a volcanic eruption on ancient Thera, now known as Santorini.

The new calibration curve, together with investigation into tree ring offsets, narrow the possible date range substantially, Manning said. Before, the “early” dates for this event were about 1628 B.C. and the “late” dates 1530-1500 B.C.

“Our modeling exercise finds the early range is much smaller and a little later than previously assessed: 1619-1600 B.C.,” Manning said. “And the later range cannot be any later than around 1540 B.C.”

Debated for years by archaeologists, the date of this major eruption, which spread ash across the Mediterranean and sent tsunamis onto the shores of Crete, has ramifications for the understanding of Bronze Age history and cultural influence in the region. A precise date for the Thera eruption would also benefit further archaeological research all over the region researchers could date sites and artifacts to the year of the eruption whenever they hit a layer of ash.

Ideally, regional versions of future international calibration curves will account for growing season differences, Manning said, leading to more accurate understanding of ancient events.

This research was funded in part by grants from the National Science Foundation and the Social Science and Humanities Research Council, Canada.


Watch the video: ECHOES - A new approach to radiocarbon dating (June 2022).


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