What causes the shift in our magnetic poles?

Question

Our megnetic north changes every million years or so and I am curious as to why and how this occurrs. Would it have anything to do with our molten metallic core moving or just due to the fact that our constant spin on our axis causes it.

Answer 1

http://www.rumormillnews.com/cgi-bin/archive.cgi?read=5588

Answer 2

The shift in our magnetic poles actually occurs far more frequently than once every million years. More like around an average of 20,000 years, although it has occurred in as short a time as 10,000 years between flip flops..

The cause of the magnetic field is due to the movement of liquid iron at very high pressures above the core and below the crust.

Be aware that often there can be more than one magnetic north or south pole, especially when the flip flop of the magnetic poles occurs.

We are currently in a phase where the magnetic field is weakening. Modern humans have never recorded a magnetic flip flop of the poles. This could create some problems for our communication systems and even our satellite systems.

Answer 3

This is due to the "dynamo" effect. Basically, a current moving through metal causes a magnetic feild and moving a metal through a magnetic feild cause a current.

The molten iron/nickel core of the Earth was probablt magnetized a little by the sun's magnetic feild. This liquid metal spins inside the earth very fast creating a current which in turn amplifies the magnetic feild which in turn increases the current so on and so forth....

So due to this intense spining, the feild flips every 25,000 years or so... the last time it flipped was 700,000 years ago however. Here is a link to a NOVA documentary on the subject. They have a slide show that demonstates how the core flips polarity.

http://www.pbs.org/wgbh/nova/magnetic/reversals.html

Answer 4

This is "shift" in the magnetic poles is created by the wobble of the earth as it rotates about its axis. The magnetic poles are part of the magnetic field generated by rotation of the Earth's core counter to the rotation of the outer layers of the Earth. They are different from the geographic poles which are the surface points marking the axis of the planet's rotation. Scientists have known that magnetic poles migrate and in the past have even swapped places. Exactly why this happens is a mystery.
The north magnetic pole was discovered in 1831 when it was revisited in 1904, explorers found that the pole had moved 31 miles.
Magnetic north actually is in constant motion and it is important to remember this when using a compass to indicate direction.

Answer 5

Most of the previous responders are close. The magnetic poles do reverse from time to time, and the presently observed decrease in the flux will probably lead to a reversal a few thousand years from now. In addition to varying in magnitude (and from time to time in direction), the field varies in the geographical position of the poles in an irregular fashion. For none of this is the exact mechanism known, but it presumably has to do with the motion of molten magnetic material far under the earth's crust. The field reversals are a useful tool for dating the ages of rocks, since a hot rock will lock in the local field when it cools sufficiently.

Answer 6

properly initially as a results of flux reversal maximum digital stuff might want to be destroyed if perfect secure practices isn't given.. yet do not problem this would by no skill take position, cos then the area station might want to be the superb of your concerns. an entire reversal of magnetic field in the international might want to outcome in maximum waves getting in opposite guidelines and what no longer.. yet i'm no longer an authority..

Answer 7

From what I learned in geo-science last year, it should have something to do with with the Earth's internal dynamo, that is, it's internal heat-source. Basically, the core has SOMETHING to do with it, but what EXACTLY, I don't know.

Answer 8

stress...stress..what an imagination...take some yoga classes

Answer 9

stress!!!