Scientists Dated the Catastrophic Pompeii Eruption Using Only Rocks. Here’s How Close They Got

According to Pliny the Younger, Mount Vesuvius erupted on August 24th, 79 CE. That date is now helping geochronologists modify a common mineral dating technique.

“Argon-argon dating” is a common technique scientists use to reveal when a geological event, such as a volcanic eruption, took place. The problem is that it’s difficult to apply to recent occurrences. To address this issue, a team of researchers looked to an ancient Roman writer for help.

In a study published Friday in Science Advances, scientists used argon-argon dating to date pumice samples from Mount Vesuvius’ eruption. They compared this age with the historical date—August 24th, 79 CE, according to Pliny the Younger, who witnessed the tragedy from a distance—which enabled them to fine-tune the calibration of the argon-argon technique. Their success in applying the argon-argon dating method to a relatively recent geological event opens the door to pinning down other recent volcanic eruptions, with implications for estimating future trouble.