Posted on 06/03/2006 7:00:13 AM PDT by ThreePuttinDude
actually, the magnetic poles have shifted significantly within the last 40 years, which is why maps and charts older than a few years are unreliable for navigation. Hell, on some land nav courses I went through in ROTC, they issued multiple degree corrections to the stated magnetic north on maps less than 15 years old.
moreover, you misread: the article stated very plainly that polar flux is highly irregular - sometimes rapid, sometimes quite static for very long periods.
The shift itself happens in circa 1000 years -- but there are long periods of stability, lasting 10,000 to millions of years. Of course, these duration estimates are based on remanent magnetism in old volcanic floes.
related topics, going back about four years, listed in alpha order:
Canada: Our North loses the Pole ~~ moving toward Siberia
Edmonton Journal | Friday, June 17, 2005 | Nathan VanderKlippe
Posted on 06/17/2005 2:18:11 PM EDT by Ernest_at_the_Beach
http://www.freerepublic.com/focus/f-news/1425129/posts
Earth Loses Magnetism
BBC | 1-1-2004 | Molly Bently
Posted on 01/01/2004 12:49:40 PM EST by blam
http://www.freerepublic.com/focus/f-news/1049919/posts
Earth's Magnetic Pole Drifting Quickly
BREITBART.COM | December 9, 2005 | ALICIA CHANG
Posted on 12/09/2005 8:05:37 PM EST by mlc9852
http://freerepublic.com/focus/f-news/1537489/posts
Earth's magnetic poles on verge of flipping
World Net Daily | December 12, 2003
Posted on 12/13/2003 11:38:30 PM EST by gitmo
http://www.freerepublic.com/focus/f-news/1039977/posts
Movement Of Earth's North Magnetic Pole Accelerating Rapidly [No Doubt Bush's Fault!]
Science Daily | 2005-12-09 | Oregon State University
Posted on 12/09/2005 3:25:52 PM EST by Brilliant
http://www.freerepublic.com/focus/f-news/1537329/posts
Sun's rays to roast Earth as poles flip
The Observer (U.K.) | 11/10/2002 | Robin McKie
Posted on 11/09/2002 8:59:37 PM EST by Pokey78
http://www.freerepublic.com/focus/f-news/786012/posts
When the compass suddenly points south ( Magnetic Pole Flip, latest SHOCKING news)
German state television | January 5
Posted on 01/05/2005 7:29:38 PM EST by Truth666
http://www.freerepublic.com/focus/f-bloggers/1314846/posts
No BS. I have to adjust the declination on my compass, and the compass on my watch, every year. Eight years ago, it was W 19.8 degrees. Now it is W 16 degrees. Magnetic north is variable.
Correct. Variation is natural. Compasses vary depending upon where one is. Deviation is caused by electro-magnetic fields, magnetic materials, iron pots and pans, engine blocks, Steel hulls, etc.
Nature varies, man deviates. It's also why the magnetic compass is used in dead reckoning. Sooner or later every sailor who depends upon it will be dead; hopefully from natural and not deviant causes.
Doubtless your previous correspondent was navigating by solar fixes, or perhaps using a Bumstead Solar Compass.
So they say.
It is very lively, not at all like the slow movement of the magma under the crust. The north magnetic pole moves continually 200-300 mph over an area radius 300 miles.
Wrong again, I'm afraid. My pevious navigating was through the use of cellestial, DR, INS, Doppler/Airmass, Pressure lines of position, Consolan, Omega, drift meter, and various other methods. I was a P-3 Patrol Plane Mission Commander and PQS instructor navigator in the US Navy, which, you'll have to admit, has a fair amount of practical navigation under its belt.
BTW, DR comes from deduced, not "dead."
I wonder why the field didn't reverse during that very long time?
According to Algore, because the Cretaceons didn't drive SUVs.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.