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New Study Improves Precision of Volcanic Dating Methods
Confirmed
In Short: Researchers at the Berkeley Geochronology Center, UC Berkeley, and the University of Padua have published a study in Science Advances detailing a new method for dating volcanic eruptions with unprecedented precision.
The study leverages historical records from Pliny the Younger, who documented the eruption of Mount Vesuvius in 79 CE, to calibrate the argon-argon dating method.
Paul Renne, a Berkeley professor and director of the Berkeley Geochronology Center, explained, “If you want to put together the eruptive history of a volcano in relatively recent time, precision and accuracy really count.”
The team tested their recalibrated method on eight samples of sanidine, a potassium-rich volcanic mineral, achieving an accuracy of 0.4% and a precision of 0.7%. This level of precision is highly unusual for more recent volcanic events.
The argon-argon method measures the decay of potassium-40 into argon-40, a process that typically occurs after a volcanic eruption.
By using Pliny the Younger’s account, the researchers were able to infer the exact date of the Vesuvius eruption, which they used to calibrate their dating method.
This new benchmark will help scientists more accurately date ancient volcanic eruptions, providing new insights into the human past and volcanic activity.
The improved precision will also aid in mitigating modern safety threats to cities like Naples, Italy, and Mexico City, Mexico, which still face volcanic risks.
Additionally, the method will enhance other dating techniques such as carbon-14 and uranium-lead, offering more accurate dates for Earth’s ancient creatures and rocks.
Renne added, “We’re hoping to really unify as many geologic dating methods as we can by using the same mathematics, the same Bayesian approach, and just bringing more data, more raw observations into that mix.”
What's confirmed
- In a recent paper published in Science Advances, researchers at the Berkeley Geochronology Center, UC Berkeley, and the University of Padua showed how they inferred an exact event date from the writings of Pliny the Younger and then used it to calibrate an argon-argon dating system.
- “If you want to put together the eruptive history of a volcano in relatively recent time, precision and accuracy really count,” said study leader Paul Renne, a Berkeley professor in residence of earth and planetary science and director of the independent Berkeley Geochronology Center.
- When the team tested their recalibrated argon-argon method for dating volcanic eruptions on eight samples and compared the results to the known dates, they found 0.4% accuracy and 0.7% precision.
- It is not available for public release until 25-Sep-2026 14:00 ET (25-Sep-2026 18:00 GMT/UTC) Thanks to the destruction of Pompeii by the volcanic eruption of Mount Vesuvius almost two millennia ago, archaeologists now have access to the most versatile and precise volcanic eruption dating method ever created.
- With this new benchmark, scientists can date ancient volcanic eruptions more accurately, providing new insights into the human past and how these deadly events unfold.
- Today, locations such as Yogyakarta, Naples, and Mexico City still face lingering threats from past volcanic eruptions.
- More accurate dating of those past eruptions will help scientists mitigate modern safety threats to these dense urban areas.
- Additionally, it will improve other common dating methods such as carbon-14 and uranium-lead, providing more accurate dates for Earth’s ancient creatures and earliest rocks.
- “The study shows that you can achieve that kind of highly useful precision and accuracy in the historical realm.” The argon-argon method is based on the decay of potassium-40 into argon-40, which typically only happens after a volcanic eruption.
- The work builds on Renne’s previous work on meteor impact and volcanic dating, also using argon-argon dating.
- By increasing the precision of those dates, his work provided new support for the idea that, within brief periods of 10s of thousands of years, roughly 66 million years ago, the Earth was bombarded with a high rate of meteor impacts that increased volcanic activity.
What's still developing
- Scientists have developed a method for detecting scrolls written with lead-based ink — the ones best suited for algorithmic analysis, according to a study published in the scientific journal PLOS.
- Hot volcanic gases instantly charred the papyri and turned them into fragile carbon.
- A new study published today in the journal Science Advances reports that the argon-argon dating method calibrated with that August 24, 79 CE is now even more precise.
- Argon-argon dating measures the ratio of atoms with the same numbers of protons and neutrons (called isotopes) inside of the element argon to determine the ages of rocks, minerals, and volcanic materials.
- “The study shows that you can achieve that kind of highly useful precision and accuracy into the historical realm.” In 1998, study co-author Andrea Marzoli of the University of Padua in Italy took new, more potassium-rich pumice samples from Oplontis.
- This evolution in methodology allowed the team to reach a precision of under 1%.
- Volcanic minerals typically contain very little argon prior to an eruption.