Scientists have long suspected that the Earth’s magnetic field might flip — switching the magnetic North and South poles — in the nearish future.
But a new study suggests that the change could happen far more rapidly than researchers thought, Space.com reports. The simulations, published last week in the journal Nature Communications, predict that the magnetic field could rotate around the planet by as much as ten degrees per year — ten times faster than anything previously theorized, 100 times faster than anything scientists actually observed, and a rate that could result in a complete reversal in less than two decades.
The problem with predicting the future of Earth’s magnetic field, which last flipped polarities about 780,000 years ago, is that it’s a gigantic, turbulent mess. The field itself is generated by electric currents stirred up by the molten metals swirling under the Earth’s surface, Space.com reports. Those factors influence one another, creating an unevenly-distributed field that fluctuates wildly.
“The flow is turbulent — in a simple sense, it could be like the flow in a pan of boiling water,” lead author and University of Leeds researcher Christopher Davies told Space.com. “So the interaction between flow and field is different from place to place within the core.”
That turbulence, which creates weak and strong spots in the field, can spur rapid shifts, the study found. While previous models suggested a total flip would take several hundred to 1,000 years, those weak spots could vastly speed up the process.
READ MORE: Earth’s magnetic field changes 10 times faster than once thought [Space.com]
More on the magnetic field: The Earth’s Magnetic Poles Are Overdue for a Switch