Map of the studied destruction layers and the different military campaigns (Image by Itamar Ben-Ezra)
The groundbreaking interdisciplinary study has been published by PNAS (Proceedings of the National Academy of Sciences of the USA) and is based on the doctoral thesis of Yoav Vaknin, supervised by Prof Erez Ben-Yosef and Prof Oded Lipschits of Tel Aviv University's Institute of Archaeology, and Prof Ron Shaar from the Institute of Earth Sciences at the Hebrew University.
Using magnetic minerals from archaeological digs, the researchers were able to reconstruct the earth’s magnetic field exactly as it was on the ninth day of the month of Av in 586 BCE, the Hebrew date of the destruction of the First Temple and the City of Jerusalem by Nebuchadnezzar and his Babylonian army.
They used the same process at 17 sites throughout Israel, alongside historical information from ancient inscriptions and Biblical accounts, to reconstruct the magnetic fields recorded in 21 destruction layers.
Mr Vaknin explained: "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.
“Moreover, we have constructed a variation curve of field intensity over time which can serve as a scientific dating tool, similar to the radiocarbon dating method.”
Burnt mud brick wall from Tel Batash (Biblical Timnah) with markings of the field orientation (Photo by Yoav Vaknin)
To illustrate the research team’s complex work, he explained how numerous dating methods have previously been used to place Hazael’s destruction of Gath - identified today as Tel Tzafit in the Judean foothills - at around 830 BCE, but had been unable to verify that his army was also responsible for the massacre of Tel Rehab, Tel Zavit and Hornet Tevet.
The new study, he said, has been able to identify full statistical synchronisation between the magnetic fields recorded at all four sites at the time of destruction, making it highly likely they were all destroyed during the same military campaign.
A destruction level at Tel Beth-Shean, however, recorded a totally different magnetic field, suggesting it was not destroyed by Hazael, as had been believed.
The magnetic data from Beth-Shean indicates the city, along with two other sites in northern Israel, was probably destroyed 70-100 years earlier, which could correspond with the military campaign of the Egyptian Pharaoh Shoshenq. Shoshenq's campaign is described in the Hebrew Bible and in an inscription on a wall of the Temple of Amun in Karnak, Egypt, and specifically mentions Beth-Shean as one of his conquests.
Burnt mud stones (Photo by Tel Aviv University)
Prof Ben Yosel said that one of the most exciting revelations thrown up by the new dating method concerns the final days of the Kingdom of Judah, a period that had been “widely debated”, he said.
“Some researchers, relying on archaeological evidence, argue that Judah was not completely destroyed by the Babylonians,” said Prof Ben Yosel. “While Jerusalem and frontier cities in the Judean foothills ceased to exist, other towns in the Negev, the southern Judean Mountains and the southern Judean foothills remained almost unaffected.
“Now, the magnetic results support this hypothesis, indicating that the Babylonians were not solely responsible for Judah's ultimate demise.
‘Several decades after they had destroyed Jerusalem and the First Temple, sites in the Negev, which had survived the Babylonian campaign, were destroyed – probably by the Edomites who took advantage of the fall of Jerusalem. This betrayal and participation in the destruction of the surviving cities may explain why the Hebrew Bible expresses so much hatred for the Edomites - for example, in the prophecy of Obadiah."
Prof Lipschits said of his team’s research work: "The new dating tool is unique because it is based geomagneti data from sites, whose exact destruction dates are known from historical source
“By combining precise historical information with advanced, comprehensive archaeological research, we were able to base the magnetic method on reliably-anchored chronology.”
Doctoral student Yoav Vaknin (Photo by Tel Aviv University)
Prof Shaar, who led the geophysical aspects of the study, as well as the development of the geomagnetic dating method, said: "Earth's magnetic field is critical to our existence. Most people don't realise that without it there could be no life on earth - since it shields us from cosmic radiation and the solar wind.
“In addition, both humans and animals use it to navigate. The geomagnetic field is generated by earth's outer core, at a depth of 2,900 km, by currents of liquid iron. Due to the chaotic motion of this iron, the magnetic field changes over time.
“Until recently, scientists believed that it remains quite stable for decades, but archaeomagnetic research has contradicted this assumption by revealing some extreme and unpredictable changes in antiquity. Our location here in Israel is uniquely conducive to archaeomagnetic research, due to an abundance of well-dated archaeological findings.
“Over the past decade we have reconstructed magnetic fields recorded by hundreds of archaeological items. By combining this dataset with the data from Yoav’s investigation of historical destruction layers we were able to form a continuous variation curve showing rapid, sharp changes in the geomagnetic field. This is wonderful news, both for archaeologists who can now use geomagnetic data to determine the age of ancient materials and for geophysicists studying the earth's core."
