Earth’s Magnetic Field Changes Directions Faster Than Previously Thought

A team of scientists was able to discover that Earth’s magnetic field changes directions about 10 times faster than previously thought. They made the surprising discovery after recreating the magnetic field’s activity during the last 100,000 years.

The discovery was made by researchers from the U.K.’s University of Leeds and the Scripps Institution of Oceanography at the University of California, San Diego. Details of their findings were presented in a new study published in Nature Communications.

Earth’s magnetic field is generated by the liquid metal in the outer core of the planet. The swirling motions of iron in the core create a field that envelopes Earth and protects it from radiation from the Sun. It also reinforces the atmosphere by deflecting highly charged solar particles or solar winds.

Since the magnetic field is affected by the movement of Earth’s liquid core, it can constantly change during periods of low activity. For instance, during extremely weak periods, the magnetic field’s north and south poles can flip. During these periods, Earth becomes more vulnerable to cosmic radiation.

It was previously believed that Earth’s magnetic field changes directions at an average of about one degree per year. However, according to a new study, it seems the directional change happens more frequently than previously thought.

Through computer models, a team of scientists recreated the magnetic field activity that occurred in the last 100,000 years. The scientists discovered that instead of one degree, the maximum rate of the magnetic field’s directional change could actually reach 10 degrees per year.

“The fastest changes that we have found generally occur in places and times when the field is unusually weak,” Christopher Davies, the co-author of the study, told Newsweek. “It is possible that the field is generally weak during reversals and so we might expect rapid changes in the field direction during reversals, but...this has not yet been investigated.”

The higher rate of directional change indicates that the magnetic field is more susceptible to experiencing polarity reversals. If this happens, Earth will lose its protective layer. Without the magnetic field, humans will be vulnerable to the harmful and lethal high-energy particles from space.