Ancient bricks inscribed with the names of Mesopotamian kings have shed light on a mysterious anomaly in Earth’s magnetic field that occurred 3,000 years ago. Published in the Proceedings of the National Academy of Sciences, the study utilized a technique called archaeomagnetism to analyze the changes in the magnetic field through the inscriptions on the bricks. This method is used to identify signatures of the Earth’s magnetic field in archaeological objects and could lead to improved dating techniques for artifacts that were previously difficult to date.
Over time, the Earth’s magnetic field weakens and strengthens, leaving a distinctive signature on minerals sensitive to magnetic fields. The research team analyzed 32 clay bricks from archaeological sites in modern-day Iraq, which were found to contain iron oxide grains with a latent magnetic signature. By measuring the magnetic strength of these grains and comparing them to the imprinted names on the bricks, the researchers were able to map the historical changes in Earth’s magnetic field.
The study confirmed the existence of the “Levantine Iron Age geomagnetic Anomaly,” a period of unusually strong magnetic field around modern Iraq between 1050 to 550 BCE. Additionally, the findings provide a new means of dating ancient artifacts based on the magnetic strength of iron oxide grains. This technique can help establish the exact reigns of ancient kings, resolving ambiguities in historical records.
One interesting discovery made by the researchers was evidence of rapid spikes in the Earth’s magnetic field intensity during the rule of Nebuchadnezzar II from 604 to 562 BCE. This highlights the potential of archaeomagnetic studies of Mesopotamian bricks to provide high-resolution insights into changes in the Earth’s magnetic field.
Overall, this research demonstrates the valuable role that archaeomagnetism can play in understanding Earth’s magnetic field and dating ancient artifacts. By analyzing inscriptions on Mesopotamian bricks, researchers have gained new insights into a 3,000-year-old anomaly and discovered a powerful tool for accurately dating ancient objects.