Magnetizations of the ocean-floor rocks alternate in direction in strips...?
547608
Parallel to adjacent mid-oceanic ridges.
264525
This is what i found on the site noted below:\n\n"There are two ways of considering what is meant by a pole shift:\n\n   1. A geological or axial shift in which the Earth’s crust literally slips around its molten core – like a loose peel on an orange – altering the positions of land masses with respect to the planet’s rotation on its axis. This could happen by a few degrees or by many degrees. Antarctica could wind up at the equator and Miami could be the new North Pole. The effects on our civilization could be devastating.\n\n   2. A shift of the magnetic poles only. As it is, the Earth’s magnetic north (the north that compasses point to) is not exactly the same as the true North Pole. This magnetic pole is not fixed and can move. In fact, scientists are fairly certain that it has shifted by as much as 180 degrees several times in the past. This change may be sudden or it may be gradual, taking place over hundreds or even thousands of years. The effects on life on the planet would probably be minimal, affecting perhaps the migratory or homing instincts of some animals.\n\nSo what about it? Is a pole shift really possible? According to A Pole Shift is the Least of Our Worries, an axial shift is possible, but “only if another planetary body – such as a ‘rogue planet’ or similar cosmic anomaly – passed in close proximity to the Earth, providing enough torque for such an event to occur.”\n\nMore likely is a magnetic shift of the poles, although there is no scientific expectation that it will happen anytime soon. But it has happened more than 180 times before, as detected in the paleomagnetic record of rocks on the ocean floor and in some lava flows. These magnetic reversals take place every 100,000 to 25 million years, according to Scientific American, and may take as long as 5,000 years to do so.\n\nSo don’t let all of this millennium madness ruin your plans for your New Year’s celebration... or your Fourth of July holiday."
934445
A molten core of super heated metal (believed to be Iron and Nickel) is spinning at the center of the earth faster than the exterior of the earth is rotating.\n\nCharged Particles create a magnetic field when they move.
358443
Natural magnetic variations and decay.  It is like waves of variation.
707879
The tectonic plates are "floating" on a liqid mantle that has convection currents.  These convection move the plates around the globe.  This is the science behing plate tectonics
85089
Imagine that you had a big globe filled with Play-Dough and that this globe had cracks in it through which you suspected that Play-Dough was regularly squished from the inside of the globe onto the surface of the globe.  You know that all of the Play-Dough on the inside of the globe spontaneously changes from red to blue at somewhat regular intervals.  Now, you notice that on the outside of the globe, around the cracks, there are stripes of play-dough running parallel to the cracks in the globe...a red strip, and then a blue strip, and then a red strip, and then a blue strip...\n\nYou could reasonably surmise that the alternating red and blue stripes were created as Play-Dough from the inside of the globe was slowly, over a long period of time, squished out onto the surface of the globe, and the stripes originate as the Play-Dough on the inside of the globe suddenly changes from red to blue and back again.  As the Play-Dough is slowly squished out, it moves the Play-Dough that was squished out before it further from the crack, so the alternating stripes of Play-Dough (the plates of the earth) are slowly moving across the surface of the globe.\n\nThe red and blue Play-Dough represents the alternating magnetism of the earth...red is, say, when North points to what we now call North, and blue, the alternate color, is when the earth's magnetism flips and and North is South.  (During one of these periods a compass on earth would point South rather than North.)\n\nHope this helps
840444
The origin of the Earth's magnetic field is not completely understood, but is thought to be associated with electrical currents produced by the coupling of convective effects and rotation in the spinning liquid metallic outer core of iron and nickel. This mechanism is generally known as the dynamo effect. \n\nBecause of the rotating outer core,it produces an electric current, which in turn, produces a magnetic field that also interacts with the fluid motion to create a secondary magnetic field. Together, the two fields are stronger than the original and lie essentially along the axis of the Earth's rotation.
51313
The clast is rotating as it's being carried along in the water, and if it hits the substrate with its edge pointing down in the downstream direction, the clast will embed.  So when you're looking at a rock with embedded clasts in it, you can determine the direction of current by measuring the maximum down dip direction on the clasts.  In other words, if the clasts are all dipping down in a certain direction, that's the direction of streamflow when the rock was deposited.
156410
Yes, it is likely that we are experiencing a reversal at this time. \n\nThe earth's magnetic field has been decreasing in field strength by about 5% per century in recent times. This is one of the fastest decreases of the magnetic field that has ever been verified. Around 700 AD the earth's magnetic field was about 50% higher than it is now. At this rate, it is estimated that the earth could reach a zero-strength magnetic field in about 2000 years. Magnetic reversals are usually triggered when the field strength approaches zero.  Another indication that some geologists and geophysicists believe may be pointing to a reversal is that the poles have been wandering at a faster rate than is commonly seen in the rock record. This instability of the magnetic field suggests we may be close to a reversal. \n\nAlso consider that since we have never experienced a reversal this is hardly a certainty. The earth's magnetic field fluctuates quite widely during what are known as 'excursions', and these are as frequent as every 50,000 years. Our current changes in the magnetic field may result in nothing more than an excursion, which is not a reversal of the field. There have been at least 11 of these excursions since the last reversal at 730,000 years before present. \n\nI've done magnetostratigraphic work.
88162
This can get quite complicated, but I do not think you want a complicated answer. \n\nThere is a force that magnets produce on each other. Like poles (two norths or two souths) repel, and opposite poles repel (one north and one south). \n\nThe forces caused by these magnetic force causes a torque to be applied to the suspended magnetic, overcoming the resistance of the string to twisting. This causes the magnetic to turn, and eventually align itself in the minimum energy position, aligned with the external magnetic field at that location, which in most places on the surface of the earth, points towards the north magnetic pole. \n\nThis is not always true, of course, because there are all kinds of complicated fine structure details to the local magnetic fields caused by buried magnetic materials nearby, such as magnetite. \n\nThe north magnetic pole is close to the geographic North pole, but not exactly the north pole, which is why in many places the compass reading has to be corrected by adding or subtracting a figure called the declination. The magnetic pole also migrates every year by a few miles, so the magnetic declination at any given location changes as a function of time as well.
1173935
Magnetic field has to do with the polarize charge of material, such as Iron.  \n\nIt is believed there is significant Iron near the center of the earth and yes rotation will cause the charges to align and thus create a magnetic field.  This is called the "Dynamo Theory".\n\nJUST BEING IRON DOES NOT MAKE THINGS MAGNETIC.\n\n"Previous theorists have assumed that the entire Core (or the Inner and/or Outer Core) rotates as a single flowing object within the Earth. If that were the case, then all of the charged (ionized) Iron material  would follow a relatively circular path around a single axis that we could call the Magnetic Axis. Basic Physics tells us that when electrical charges follow a closed (relatively) circular path (which is effectively a current), a magnetic field is always created as a result. The measurable evidence of this scenario would be a simple "dipole" magnetic field, with a single North Pole and a single South Pole, geographically exactly opposite each other on the surface of the Earth."\n\nSo if this theory where correct the Earth stopping it's rotation would in allow the magnetic field to fad.  But there are major problems with the theory.  For example it is known that the magnetic poles have flipped (Switched places) several time in Earths past.  Will if we have magnetic poles because of the earth's rotation to switch poles we'd need to reverse the cores rotation.  This would be an ungodly amount of energy.  There is nothing known that would do this once let alone a number of times.  And even if something could do it, we should have seen signs of the massive damage that would have resulted with these forces in play, like the Earth falling apart.   But in fact the poles shifting seems to be a pretty peaceful process on a planetary scale. \n\nAnd that is only one problem with the theory.  This is actually a very, very complex subject and there really is no way to know what effect the Earth stopping would have on the magnetic fields.  But I have attached a link to a very good article on the subject and it's pretty easy reading (Keeps the scientific jargon down and uses layman terms.)\n\nOthers are correct tough in what holds us to the Earth is gravity, not magnetics.  So it's the Mass (How big and dense it is) that keeps us here.  And rotation actually wants to make thing's fly away from it.  So we stay because the Earths gravity overcomes the acceleration.  So the acceleration of 1000mph is actually always enacting upon us, making us want to fly off the planet.  So stopping the Earth will not make us fly off as others have posted.\n\nThink of the spinning rids at the fairs and theme parks.  When you spin you are thrown away from the axis, the best example is the cylinder you go in and stand up against the wall.  When it spins your back is pushed against the wall, even as it turns so you are now spinning vertically like a tired, instead of horizontal like a top.  But when they stop the ride you don't go flying out.  That's because the wall holds you in and your move with the ride.  Well gravity acts like the wall and you move with the earth.\n\nYou would go flying of the earth if it continued to rotate and the gravity field somehow disappeared.
991202
These materials have areas within them call domains. Each domain has a magnetization that is pointed in a certain direction; when groups of domains are pointed in the same direction, the material is magnetized in that area (in the direction the domains are pointing).
108424
Earth's magnetic field (and the surface magnetic field) is approximately a magnetic dipole, with one pole near the geographic north pole and the other near the geographic south pole. An imaginary line joining the magnetic poles would be inclined by approximately 11.3° from the planet's axis of rotation. The cause of the field is probably explained by dynamo theory. The magnetic field extends several tens of thousands of kilometres into space as the magnetosphere\n\nThe locations of the magnetic poles are not static but wander as much as 15km every year (Dr. David P. Stern, emeritus Goddard Space Flight Center, NASA). The two poles wander independently of each other and are not at directly opposite positions on the globe. Currently the south magnetic pole is farther from the geographic south pole than the north magnetic pole is from the north geographic pole.\n\nThe field is similar to that of a bar magnet, but this similarity is superficial. The magnetic field of a bar magnet, or any other type of permanent magnet, is created by the coordinated motions of electrons (negatively charged particles) within iron atoms. The Earth's core, however, is hotter than 1043 K, the Curie point temperature at which the orientations of electron orbits within iron become randomized. Such randomization tends to cause the substance to lose its magnetic field. Therefore the Earth's magnetic field is caused not by magnetised iron deposits, but mostly by electric currents in the liquid outer core.\n\nAnother feature that distinguishes the Earth magnetically from a bar magnet is its magnetosphere. At large distances from the planet, this dominates the surface magnetic field.\n\nElectric currents induced in the ionosphere also generate magnetic fields. Such a field is always generated near where the atmosphere is closest to the Sun, causing daily alterations which can deflect surface magnetic fields by as much as one degree.\n\nMagnetic field variations\n \nGeomagnetic variations since last reversal.The strength of the field at the Earth's surface ranges from less than 30 microteslas (0.3 gauss) in an area including most of South America and South Africa to over 60 microteslas (0.6 gauss) around the magnetic poles in northern Canada and south of Australia, and in part of Siberia.\n\nMagnetometers detect minute deviations in the Earth's magnetic field caused by iron artefacts, kilns, some types of stone structures, and even ditches and middens in geophysical survey. Using the magnetic instruments adapted from airborne devices developed during World War II to detect submarines, the magnetic variations across the ocean floor have been mapped. The basalt -- the iron-rich, volcanic rock making up the ocean floor -- contains a strongly magnetic mineral (magnetite) and can locally distort compass readings. The distortion was recognized by Icelandic mariners as early as the late 18th century. More important, because the presence of magnetite gives the basalt measurable magnetic properties, these magnetic variations have provided another means to study the deep ocean floor. When newly formed rock cools, such magnetic materials record the Earth's magnetic field.\n\nIn October 2003, the Earth's magnetosphere was hit by a solar flare causing a brief but intense geomagnetic storm, provoking unusual displays of aurorae.\n\nMagnetic field reversals\n\n\n\nMain article: geomagnetic reversal \nBased upon the study of lava formations in Hawaii, it has been deduced that the Earth's magnetic field reverses at intervals, ranging from tens of thousands to many millions of years, with an average interval of approximately 250,000 years. The last such event, called the Brunhes-Matuyama reversal, occurred some 780,000 years ago.\n\nThe mechanism responsible for geomagnetic reversals is not well understood. Some scientists have produced models for the core of the Earth wherein the magnetic field is only quasi-stable and the poles can spontan
675424
the earth has a molten metallic core that's spinning...creates an em field
895350
Direction of Magnetic fields are in North To South direction\nIn a circular ring magnet, the direction is Clockwise in N-S Direction
687020
yes, just take a conical mold, pour in some molten iron, and keep it in a magnetic field as it cools. north and sout poles WILL be opposite sides, but it could have a weird overall field.
608387
The Earth's center contains a lot of molten iron; due to Earth's rotation, it rotates too, thus generating a magnetic field. It's bit more complicated, but in a nut that's the explanation.