Earth's magnetic field may not be heading toward a dramatic flip anytime soon, according to scientists who analyzed anomalies in the planet's invisible shield against solar wind and other radiation.
Earth's magnetic north and south poles switch at irregular intervals at an average of every 200,000 years or so, and the event could have a dramatic effect on the environment and technology.
There had been speculation that the next flip was close because of the South Atlantic Anomaly, a mysterious area in which the magnetic field is unusually weak. However, this anomaly may not indicate that a weakening and switching of the magnetic field are imminent, according to a new study.
"We have mapped changes in the Earth's magnetic field over the past 9,000 years, and anomalies like the one in the South Atlantic are probably recurring phenomena linked to corresponding variations in the strength of the Earth's magnetic field," Andreas Nilsson, a geologist at Lund University and co-author of the study, said in a statement.
The results are based on analyses of burnt archaeological artifacts, volcanic samples and sediment drill cores, which contain information on the history of Earth's magnetic field.
The team from Lund University used these data to develop a model that recreated the direction and strength of the magnetic field at specific places and times.
"Based on similarities with the recreated anomalies, we predict that the South Atlantic Anomaly will probably disappear within the next 300 years and that Earth is not heading towards a polarity reversal," Nilsson said.
The study was published June 6 in the journal PNAS.