Shifty Poles: When Magnetic Poles Flip

February 5, 2018
North Pole

When most people think of the North Pole, they think of Santa Claus and his workshop of jolly elves.

Other folks, more paranoid, think of the Mayan calendar, and the warnings that the magnetic poles will flip and annihilate life on Earth. Few think of the real fact that last year the shifting magnetic north pole closed down an airport in Florida!

The North Magnetic Pole is shifting from Canada to Russia. Source: NASA

You see, while the actual North Pole, the axis that the Earth spins, is very stable, the magnetic north pole is always on the move. Historically it moves roughly 6 miles (10 km.) a year. It used to be right over Canada’s north coast. Now it is drifting through Canada’s Arctic Islands towards Russia. This makes it awkward if you are using a compass to navigate, as airplanes do.

Last year, Tampa International Airport had to close its runways because of the shift. Airport runways are labeled with their compass directions to help landing pilots. For example, for decades their main runway was Runway 18R/36L, indicating its alignment along the 180˚ approach from the north and the 360˚ (due north). By last year, the magnetic north pole had moved so much that the compass readings had changed 10 degrees and they had to rename the runway 19R/1L on aviation charts.

This movement, however, is minor. In the past we’ve seen the magnetic poles flip, so that compasses that pointed to the North Pole would point towards Antarctica! Geological records shows the poles usually flips about every 300,000 years.

The sloshing liquid core of the Earth moves the magnetic poles. Source: NASA

Remember, the real axis of the spinning world has not shifted. What is moving is the axis of the iron core of the Earth. The spinning of the molten iron core generates the Earth’s magnetic field.

Liquids slosh. Huge earthquakes and meteor strikes cause the liquid core to ripple and slosh around, changing the poles. Sometimes whirlpools form, creating multiple north and south poles. Currently there is a weird area with almost no magnetic force off the coast of Brazil, called the South Atlantic Anomaly.

When magnetic poles flip Source: NASA

When poles flip, geology shows they go from two poles, to multiple poles, back to two poles that have changed hemispheres. The process takes thousands of years. Life forms have lived through the shift multiple times.

So if the Doomsday prophets are right and the poles flip—don’t expect much in the way of doom and gloom. It might just mean that our great-grandchildren will watch the Northern Lights from sunny Florida.

About This Blog

The column, “Weather Whispers,” is authored by James Garriss and Evelyn Browning Garriss, historical climatologists and weather addicts!  Whether you enjoy the science of weather or the fascinating folklore or just fun weather phenomena, it’s probably covered by these weather watchers!