A study of pottery made during the Iron Age, 750 B.C. to 150 B.C., shows a record of the Earth’s magnetic field and how it fluctuated during those years, which could help scientists understand the field’s current actions.
Scientists from Hebrew University, Tel Aviv University, and the University of California studied 67 jars made over the 600-year period in Judea to determine the strength and direction of the magnetic field during that time period, according to Science Times.
When the pots were heated in the kiln and then cooled, the iron inside the clay froze in place and created a record of the strength and direction of the magnetic field at that time in history, Science Times reported.
Although many jars cannot be precisely dated with any accuracy, the jars studied had royal stamps on them and can be dated within 30 years or fewer.
According to the jars, the magnetic field was about 40 percent stronger then than it is now. Around 700 B.C., however, the field’s strength got about 50 percent stronger all at once, then fell back to about its normal intensity over the next three decades, according to The New Yorker.
Such a jump today would likely disrupt the power grid and satellites that govern cell phone and other communications, but in 700 B.C., the people probably didn’t even notice, The New Yorker said.
The findings of the study may help scientists be more precise in their carbon dating efforts and understand the magnetic field and its fluctuations better. The field has decreased in intensity at about 6 percent per century since scientists have been measuring it, the New Yorker said.