Posted on 12/21/2007 3:13:32 PM PST by blam
North by Northwest
The planet's wandering magnetic poles help reveal history of Earth and humans
Sid Perkins
Hikers in the wilderness often place their faith in a trusty compass. But any navigator worth his salt knows that compasses can't truly be trusted: Only along certain longitudes in the Northern Hemisphere does a compass needle point due north.
MOVED BY MAGNETISM. Explorers first found the north magnetic pole at Canada's Cape Adelaide in 1831. Blue dots (direct surface observations) and red dots (models using satellite data) denote the pole's movement since then. Green dots indicate the pole's future location if its current rate and direction of motion continue. Olsen and Mandea
In other locales, a compass needle slews either to the left or the right of true north by a certain angle, a process commonly known as declination. That's because a compass isn't attracted to the north geographic pole, the point at which Earth's rotational axis pierces the Arctic ice. Instead, the needle is attracted to the north magnetic pole, the spot where the planet's invisible magnetic field lines burst from the surface and point directly upward.
Astronomers have long known that a compass doesn't always point true north, a bearing in the night sky that lies within 0.5° of Polaris, the North Star. Their measurements of declination, along with those made by seafaring explorers, enabled 16th-century sailors to better navigate along their trade routes, especially those linking the New World to the Old. What many scientists didn't appreciate until the 1600s, after they had compiled a few decades' worth of precise measurements at astronomical observatories, was that declination varied through time. Suddenly, they realized: The magnetic pole moves!
What difference does this make in today's world, where pilots, navigators,
(Excerpt) Read more at sciencenews.org ...
GGG Ping.
Pole dancing?
Interesting. I had no idea the location of our magnetic poles varied so widely by year.
drift happens. cool.
BumP
A very moving article!
Great post! Wonder how this constant moving affects migrating birds?
Hmmm, so when does it flip from N to S pole, when it gets nearest the North pole?
True Virgins Make Dull Companions At Weddings.
Can Dead Men Vote Twice At Elections?
Canada no longer the true north?
National Post | March 16, 2002 | Siobhan Roberts
Posted on 03/19/2002 3:16:17 PM EST by Oxylus
http://www.freerepublic.com/focus/f-chat/649505/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
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
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
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
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
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
Earth’s magnetic pole shifting; Alaska may lose northern lights
Rapid City Journal | 8 Dec 05
Posted on 12/09/2005 12:19:41 AM EST by rellimpank
http://www.freerepublic.com/focus/f-news/1536903/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
Reversal of Earth’s Magnetic Field-(Hey Algore read this)
Projects in Scientific Computing | Gary Glatzmaier, Los Alamos Nat’l Lab
Posted on 06/03/2006 10:00:13 AM EDT by ThreePuttinDude
http://www.freerepublic.com/focus/f-news/1642780/posts
related to #1536903 above:
Energy source of northern lights found
AP on Yahoo | 12/11/07 | AP
Posted on 12/11/2007 7:57:54 PM EST by NormsRevenge
http://www.freerepublic.com/focus/f-chat/1938148/posts
this seemed a little dim-witted:
Wandering Hot Spots Worry Geologists
New Scientist | 12-18-2001 | Betsy Mason
Posted on 12/18/2001 7:04:43 AM EST by blam
http://www.freerepublic.com/focus/fr/592781/posts
[snip] The researchers measured the direction in which the minerals in the volcanic rocks of the islands were magnetised. When the lava flows that formed the islands cooled and solidified, the minerals lined up with the Earth’s magnetic field, providing a record of their location at the time. [end]
This one was interesting, because one scientist claims that the Chandler Wobble is caused by the winds (I’m not making that up) and that global warming will make it worse. :’D
Chandler’s Wobble Causes Earthquakes, Volcanism, El Nino, and Global Warming
Michael Wells Mandeville | 2004 | Michael Wells Mandeville
Posted on 01/18/2005 11:58:05 PM EST by IGBT
http://www.freerepublic.com/focus/f-news/1323583/posts
and then there’s this:
Serious Climate Change: Winds Blew in Reverse During Last Ice Age
Live Science | 1-23-07 | Andrea Thompson
Posted on 01/24/2007 10:50:30 AM EST by jcb1379
http://www.freerepublic.com/focus/f-news/1772866/posts
Hey, these are just scratching the surface of what I found around here. :’D
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Thanks Blam. A bunch of related topics linked here. :') |
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sort of related to the Chandler Wobble topic linked above:
The ‘wobble’ that wipes out life on Earth every 2.5m years
The Daily Mail | October 12, 2006 | Julie Wheldon
Posted on 10/12/2006 2:43:56 AM EDT by MadIvan
http://www.freerepublic.com/focus/f-news/1717922/posts
and hey, why not this one too:
Burping Moon may solve magnetism mystery
News in Science | Jan 16 2003 | Abbie Thomas - ABC Science Online
Posted on 02/19/2003 3:55:20 PM EST by vannrox
http://www.freerepublic.com/focus/f-news/847039/posts
The angle between the magnetic and geographical pole is called variation, not declination.
Wonder how this constant moving affects migrating birds?
Gives 'em Vertigo!
Webster’s Dictionary has both declination and variation for the angle between the magnetic and geographical pole, but when I was in the Air Force we always called it variation.
I am impressed by how rapidly the movement of the North magnetic pole is accelerating.
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