Aqui está uma curta nota que vi na Nat. Geo. que me pareceu interessante dada a nossa actividadede geocaching.
Projecta-se que se o polo norte magnético em 2050 estará na Sibéria e não no Canadá onde está hoje.
Leiam o artigo e vejam a imagem que é bastante elucidativa.
The Vaulting Pole
All compasses point to the north magnetic pole-but it might be time to trade that trusty compass for a handheld GPS. The north magnetic pole, unlike the stable geographic pole around which the planet spins, is hightailing it toward Siberia at a clip of 25 miles a year. Generated by movement of liquid iron coursing through Earth´s outer core, the north magnetic pole has moved some 700 miles since its discovery in 1831. Oregon State University paleomagneticist Joseph Stoner´s analysis of magnetic minerals in Arctic lake beds indicates that, today´s polar speeds are faster than any since thEli15th century. The most notable impact of its wandering is likely to be on the pole´s colorful halo, the aurora borealis, which may soon be more risible in Russia than Alaska. "A hundred years, ago this movement could have been a major /problem for navigation," Stoner says. "Now it´s " a minor inconvenience." -Joel K. Bourne, Jr.
De NATIONAL GEOGRAPHIC, DEC. 2006, pg. 31