Friday, January 07, 2011

Poles Shifting

It seems that the pole that we consider magnetic north is shifting. As it turns out and the linked article explains, this is natural and normal, it's just moving faster than usual. If it keeps up this rate of change, the magnetic north pole will be under Siberia in fifty years.

However, that means that your compass doesn't point north, not that it ever did. If you look at a decent map, on the bottom will be something called a declination diagram that tells you how far off of true north your compass will point.

Declination diagrams were something I spent a lot of time studying as a youth, leading platoons through thick undergrowth. We had to know where we were, and if we didn't pay attention to the little variances between grid north and magnetic north, we'd soon be lost. There is a reason that they normally give young lieutenants a senior Sergeant to go along with that map and compass, and being lost is the reason.

Nowadays, with GPS technology it's increasingly harder to get lost, but we manage. Still, it's interesting that the poles are moving, and if you're doing old-style land navigation, it would help to have a current declination. In the United States, it's shifting west.

1 comment:

Anonymous said...

I cannot for the life of me find it again, but some Progressive with a terminal case of recto-cranial insertion said it was somehow Bush's doing, heaping epithets on him. I think if someone had the power single handedly to change Earth's magnetic orientation, I'd do everything in my power to make him my bestest buddy in the whole wide World, not call him names.

Gerry N.