While that may sound dramatic, renowned science journalist Alanna Mitchell’s book “The Spinning Magnet“ revealed that the next time Earth’s magnetic field flips, it could seriously damage the electric infrastructure that defines our modern civilization.
What is an Electromagnetic Field?
While magnetism is fascinating, it has also been historically misunderstood. According to Physics.org, Earth’s magnetic field exists because the planet’s solid iron core is surrounded by liquid metal.
According to NASA, the flow of liquid iron in Earth’s core creates electric currents that generate the magnetic field. This electromagnetic field provides an invisible shield that blocks solar and cosmic rays.
Earth’s magnetic poles have reversed many times in the past, but scientists can’t predict when the next reversal will occur. In other words, a magnetic field flip is coming, we just don’t know when.
To find evidence of the magnetic past, scientists examine ancient rocks. Certain minerals in lava flows are sensitive to Earth’s magnetic field as the lava cools; scientists analyze the rock samples to uncover a record of Earth’s magnetic field, according to National Geographic.
Scientific American noted that in the past 200 million years, reversals have taken place approximately every half-million years. The last reversal happened around 780,000 years ago, so we’re due for a flip.
Potential Geomagnetic Reversal Effects
What are the potential outcomes of swapped North and South Poles? Compass needles would be wrong, and animals that use Earth’s magnetic field for navigation — such as birds, salmon, sea turtles, whales and butterflies — could get temporarily disoriented, according to National Geographic.
Mitchell warns that a reversal could destroy anything electronic, including home appliances, satellites, wireless devices and the electric grids that make all these items work.
In an essay on Undark.org, Mitchell wrote, “We have blithely built our civilization’s critical infrastructure during a time when the planet’s magnetic field was relatively strong, not accounting for the field’s bent for anarchy.”
With a weak electromagnetic field, radiation from space could possibly make some regions of Earth uninhabitable and cause entire species to go extinct. But first, according to Mitchell, we would have problems with sensitive orbiting satellites, which control electric grids and could cause “a domino run of blackouts that could last for decades.”
What Does the Future Hold?
The good news is that we have plenty of time to prepare. The bad news? The magnetic field is much weaker, as low as a tenth of its normal strength, according to Futurism. A gradual change could mean that we’ll have years without the invisible protective shield between Earth and space.
It’s not all doom and gloom, though. We don’t know whether this will occur in our lifetime. Even if it does, the flip could take hundreds of years, and geomagnetic reversal effects would be mostly gradual.