NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Annual Increase of Variation
From: Brian Whatcott
Date: 2002 Feb 13, 07:12 -0600
From: Brian Whatcott
Date: 2002 Feb 13, 07:12 -0600
At 06:40 AM 2/13/02, Dave Weilacher wrote: >It is my understanding that the magnetic north pole lives at somewhere >around 75 north by 95 west; this being the area that most compasses point >to. (except french ones I'm told). > >The "pole" is moving west approx 1 degree of longitude per >year. Longitude where we are is pretty far compared to 75 north plus a 1 >degree change in longitude that far away makes for a very small great >circle correction to us. > >I would still like to know if there is a geographical position of the pole >that I could use to reduce a variation. I have seen a chart showing the irregular loops that describe the long term locus of the north magnetic pole. I understand the US mapping authority provides a new chart of isogonals each ten years. I suppose that if you look at the northern confluence of the isogonals on a current chart of this kind, you have the best estimate of the magnetic pole as of the date of publication. Brian Whatcott Altus OK Eureka!
