Shifting poles

1 February 2019

The Earth's poles are shifting! Are we all doomed?

Probably not.

One of the things the Earth has always had is a magnetic field. It's mostly caused by the molten core inside the Earth and how it swirls about deep underground.

It protects us from solar radiation, produces the most awesome auroras, and it might help migratory birds know what direction to go.

It also helps us navigate using magnetic compasses. This includes using a compass to align an equatorial mount (see my blog).

The magnetic field generated by the Earth isn't fixed, but wanders around slowly as the swirls in the Earth's core change their behaviour from year to year. However, in the last few years, there's been a noticeable increase in its rate of change.

So what's going to happen?

It's hard to say. Because the poles are wandering randomly about, rather than going in a consistent direction, it's difficult to predict what's going to happen. But, because the poles are hardly speeding (they're doing maybe 15 kilometres per year) whatever is going to happen probably won't happen soon. Of course that doesn't stop some people from going off the deep end.

I'm not sure what the effect is going to be on the birds, but navigators will be fine. GPS systems don't work on magnetic fields. It's true that satellites will be effected by cosmic and solar radiation, but if it starts to be a problem, newer satellites will have additional shielding built in.

More significant are magnetic anomalies such as iron-rich mountains. These are a problem in my outback geocache.

So how do we deal with this? Like Randall Munroe says, we can update the magnetic declination maps.

When you're aligning your equatorial mount using a compass, make sure you look up your local declination and correct the magnetic compass reading to find true south.