The Earth’s magnetic field is not constant. The flips where it suddenly reverses direction are a crucial tool in dating geological events. Now, some researchers claim they can use even brief changes in the field’s strength to precisely date the destruction of cities, and then use these dates to test Biblical accounts.

The second book of Kings is not one of the more widely read or famous parts of the Bible, but the battles it describes are of interest to historians. They are, after all, considerably more plausible than tales from earlier books such as Noah’s Ark, even if victories are attributed to divine intervention.

Archaeological digs have managed to match a number of sites to cities (villages by modern standards) referred to in the Bible as being destroyed by various hostile neighbors. In a new study, University of Tel Aviv doctoral student Yoav Vaknin and co-authors show that the destruction of these cities fits with Biblical accounts.

When magnetic substances get hot enough, they retain the local magnetic field as they cool. Today, that magnetic field is often supplied by electric powerlines or other artificial sources, but three millennia ago the Earth’s magnetic field was pretty much the only game in town. So, when pillaging armies burned towns, the layer of ash that marks their “destruction zone” carries a record of the intensity, as well as the direction, of the Earth’s magnetic field at the time.

"Based on the similarity or difference in intensity and direction of the magnetic field, we can either corroborate or disprove hypotheses claiming that specific sites were burned during the same military campaign,” said Vaknin in a statement emailed to IFLScience. The fact that the geomagnetic field was changing unusually rapidly in this region 3,000-2,600 years ago, sometimes spiking by more than double the current intensity, makes the process easier.

The Bible refers to the Philistine city of Gath, just beyond the borders of Judea, as being destroyed by Hazael, King of Aram-Damascus. Archaeologists believe the Tell es-Safi site in what is now central Israel is the remains of Gath, and was burned around 830 BCE.

The Bible also blames Hazael for the fall of three other cities, thought to be the places now known as Tel Rehov, Tel Zayit, and Horvat Tevet.

Vaknin and co-authors can’t pin the blame on an individual, but they do claim to have shown that the magnetic field was the same when Gath and the other cities burned, indicating it was probably in the same year. By Occam’s razor, it would seem likely the same hand was at play. 

On the other hand, the destruction of Tel Beth-Shean (now northern Israel) has also been attributed by some modern scholars to Hazael. However, Vaknin’s data suggests its demise came 70-100 years after that of Gath, by which time Hazael was certainly dead. Tel Beth-Shean’s fall coincides with the campaign of Pharaoh Shoshenq into the lands east of the Mediterranean.

The work also supports the theory that parts of the kingdom of Judah survived after the Babylonians destroyed Jerusalem. “Towns in the Negev, the southern Judean Mountains and the southern Judean foothills remained almost unaffected, said co-author Professor Erez Ben Yosef. “Now, the magnetic results support this hypothesis.”

These cities fell decades later, and the authors attribute their destruction to the Edomites rather than the Babylonians. Ben Yosef suggested this might be why the Bible, seldom complimentary of any neighbors of the Kingdom of Judah, reserves particular hatred for the Edomites.

However, the fact the Bible could present an accurate account of events that occurred not long before it was written does not necessarily say much about how well it covers the thousands of years before that.

The paper is published in Proceedings of the National Academy of Sciences.