Researchers from Israel, Italy, and the United States, based on the analysis of archaeological finds, recreated the magnetic moment of the Earth that existed in the Neolithic. The scientists’ article was published in the journal Proceedings of the National Academy of Sciences.
Experts analyzed 129 tools made of flint and fragments of ceramics aged from eight to ten thousand years, found on the territory of the archaeological site of Wadi Feynan in Jordan. In these ancient objects, information about the magnetism of the past remains “frozen” in tiny crystals of ferromagnetic minerals, from where it can be “extracted” in laboratory conditions.
The researchers found that the Earth’s magnetic moment — the main physical quantity that characterizes the ability to create and perceive a magnetic field – was relatively small in the Neolithic but then increased dramatically. Back in 7600 BC, it was about two-thirds of the current one, but by 7000 BC, its strength was greater. After 5200 BC, the magnetic moment began to weaken gradually.
The results of the study are important, the researchers emphasize. The Earth’s magnetic moment gradually decreases over the time of its measurement (about 200 years). This raises concerns that the planet may at some point completely lose its magnetic field.