| MadSci Network: Earth Sciences |
The term "magnetic pockets" is not technically precise, so I will use "magnetic anomaly" to describe variations in the magnetic field of our planet.
Earth like many planets has an overall magnetic field rather like a bar magnet, with a well defined North and South pole. There are also small local deviations from the smooth field, or magnetic anomalies, as well as fluctuations due to magnetic storms from the sun. For example, Thule, Greenland, is known for unusual radio propagation due to these. See my web site http://www.altair.org/atmoelec.h tml for more.
Other planets like Mars have no large-scale planetary magnetic field, but are speckled with small local fields sometimes called "magnetic pockets". See http://mor e.abcnews.go.com/sections/scitech/surveyor1209/ for more.
A map of local magnetic variations in the continental USA from USGS web
site at http://minerals.usg
s.gov/news/v1n2/3aeromag.html providing low
altitude aeronautical surveys, including Eastern seabord Atlantic and the
Bermuda Triangle is
In all, these variations are pretty small compared to the total field, that is, no local effect dominates the overall field in any location.
As far as Leedskalnin's Coral Castle, it is a fascinating story, but magnetism does not explain it, nor do any of the four forces known to science. If you must believe this legend, then you must postulate a fifth force, not magnetic, but perhaps one that is similar to and often mistaken for the magnetic force. This is especially true since coral is not ferromagnetic, that is, coral is not significantly subject to the magnetic force. A local magnetic force strong enough to lift tons of coral by magnetism would draw nails and bolts at the speed of sound from great distances. If the legend of Coral Castle is ture, it is a force other than magnetism. Best Regards, Altair
Try the links in the MadSci Library for more information on Earth Sciences.