Did You Know? - The North Magnetic Pole's on the move
The Geographic North Pole sits on top of the world at latitude 90 degrees North. But the North Magnetic Pole (which a compass needle points to) is further south, at 85 degrees North - at least for now. It won't be sticking around though.
Heading for Siberia
The North Magnetic Pole is moving north, at about 40km per year. In the past 100 years it has travelled about 1,100 km. At that rate it will be in Siberia in 50 years.
Magnetic, but unpredictable
But no one knows whether the pole will keep travelling at the same speed. It might slow down. It might even head off in another direction.
A world attraction
Imagine a bar magnet with one end in the northern hemisphere and the other in the southern hemisphere, with its middle crossing the centre of the earth. When you're standing over the north end of it you're at the North Magnetic Pole.
Plugged in at the centre of the earth
The earth's core is mostly molten iron. There's so much pressure down there, squeezing the molecules together, that that the inner core is solid. It doesn't rotate at the same speed as the outer core. The outer core is boiling liquid iron, and the lighter elements rise while the heavier ones sink, like grains of rice in boiling soup. All that commotion generates electrical currents, like rubbing your foot on a carpet. This creates a magnetic field.
The earth's magnetic field (credit: Natural Resoures Canada)
Okay, but why is the magnetic pole moving?
There are probably a few different causes. It has to do with the way the magnetism is generated.
Well that's not much of an answer!
All this is happening thousands of kilometres below your feet. It's a long way down, there is tremendous pressure, and then there's the temperature -- 4800 degrees Celsius, to be exact. Nobody has gone down to check it out yet. Any volunteers?
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