The Truth About True North
Look out Santa! We’ve got some surprising news that’ll knock your (woolen) socks off!
You know that trusty, dusty compass you’ve counted on to show you the way? Well, it might not be so trustworthy, after all.
See, your compass works because a magnetic pin inside spins freely, its north-seeking end aligning with the Earth’s magnetic field to indicate Magnetic North (remember, opposite poles attract).
Sounds good? Just whip out your compass and head straight to the North Pole, right?
Well…not so fast!
The first problem is that the compass doesn’t point to the Geographic North Pole (or True North)—the fixed point where the Earth’s axis of rotation meets the surface.
Instead, it points to the Magnetic North Pole, a separate location in the Arctic Ocean that is currently hundreds of miles away from True North (heading toward Siberia).
This difference between the direction the compass points and True North is called magnetic declination.
The second problem is that the Magnetic North Pole is moving! It has shifted more than 600 miles in the last 100 years, and its speed has accelerated dramatically in recent decades.
Scientists believe that the Earth’s magnetic field is generated by the dynamo effect—the flowing currents of molten iron in the planet’s outer core. Because these currents are constantly shifting, the Earth’s magnetic field is not fixed.
As a result, the Magnetic North Pole moves around 55 km (34 mi) a year, sometimes more! In fact, at some point in time (geological time, not lifetime time…thankfully), the Earth’s North and South magnetic poles might flip completely, as they did 780k years ago!
In other words…hold on to your hat, Santa! 🎅💫🌀😵💫
Tags: compass , earth’s core , Earth’s magnetic field , magnetic compass , magnetic field , magnetic poles , north pole , true north
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