Wednesday, November 22, 2006

The Shifting North Pole

The December 2006 National Geographic has an amazing map of the 700 mile movement of the North Magnetic Pole since its discovery in 1831. If it keeps on moving like it has in the past, it will be in Russia in a few years. The accompanying notes by Joel K. Bourne, Jr. indicates the pole is moving at a rate of 25 miles a year! The article suggests that "... it might be be time to trade that trusty compass for a handheld GPS."

Actually, compasses are very reliable on a day to day basis while GPS receivers are subject to periodic outages and loss of signal under certain conditions. I recommend carrying both into the field. A magnetic compass needs no batteries, while a GPS offers a large number of navigation and tracking tools.

I looked on the National Geographic web site to see if the map in the magazine is online. As of today it isn't. But they do have this news article from last December describing research by Joe Stoner, a paleomagnetist at Oregon State University. He has found that the movement of the pole is completely normal. It gives researchers a window into the liquid iron core at the center of the earth. It also influences the aurora borealis!

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