Earth’s geographic axis is defined by a straight rod of metal embedded in the earth at the North Pole.
Earth’s magnetic axis, however, is not located precisely due north of this point but has been observed to drift from it over time.
In addition to this, the magnetic field of Earth can be expected to change in response to changes in either or both of two factors: the total amount of magnetism generated internally and externally, and where that magnetism happens.
Here is the answer for, how are earth’s geographic and magnetic axes oriented relative to each other?
However, while these factors are typically slow-changing phenomena–they do occasionally change quickly enough that we notice them happen!
This can happen when large amounts of molten rock come together under Earth’s surface during periods when global tectonic activity increases.
Here are some points about the relation between earth’s geographic and magnetic axes-
1. Earth’s magnetic axis is not a straight line
The geographic axis is a straight rod of metal embedded in the earth at the North Pole. Earth’s magnetic axis, however, is not located precisely due north of this point but has been observed to drift from it over time.
In addition to this, the magnetic field of Earth can be expected to change in response to changes in either or both of two factors: the total amount of magnetism generated internally and externally, and where that magnetism happens.
The relation between the two axes is approximated by our magnetic poles which can be found by dividing $90^\circle$ into 360 degrees.
These lines, which run between the magnetic and geographic poles of the Earth, define the magnetic equator and magnetic meridian.
2. Earth’s magnetic axis is not straight
Earth’s magnetic axis is tilted with respect to its spin axis by about 11 degrees and it undergoes a complete reversal every 200,000 years on average.
This means that if you were to look at a drawing of our planet’s geomagnetic poles since the last reversal, you would see that they continually move around in a circle while trending toward one point on the circle which is 11 degrees from where we currently observe them to be.
Here is an image of the direction in which the magnetic poles are moving right now.
3. Earth’s magnetic axis is slowing down
For any given location on Earth, the direction in which the magnetism generated by the planet’s internal molten metal is pointing has been observed to change slowly.
This change occurs because of a slow-changing phenomenon called “dipole tilt.” By measuring how easy it is to point a compass needle in different directions, geophysicists can estimate how much earth’s interior magnetism has changed since records of it were established some 400 years ago. The result for this analysis is shown below.
4. The magnetic poles move around Earth rather than staying still
Magnetic poles not only drift around the planet, meaning that we do not observe them to stay in one place but they also appear to be moving north and south over time.
Although this occurs slowly, it has been observed that instead of repeating themselves exactly after repeating themselves once every 200,000 years, the places where the magnetic poles are located move slowly every 1,000 years.
This means that a person standing at a certain point on the globe will see the pole swing by a little before it swings back again at a different point immediately to its left. This image shows how our poles move over time.
5. The magnetic poles are not fixed
The poles move. The diagram below shows how the north pole of Earth’s magnetic field has moved over time.
You can see that each point on the globe is marked with a coordinate system which defines the direction that the magnetism generated by our planet’s molten interior metal takes at that location. This kind of coordinate system is called a “prime vertical.”
And it may be surprising to learn that our geomagnetic poles are not fixed in place, exactly, when we look at world maps from ancient times.
This is because those maps show the north magnetic pole as being at a different location than it actually is today. The images below show the difference in the locations where our poles were at flip-flop times–200,000 and 90,000 years ago respectively.
6. Earth’s magnetic field has changed over time
By measuring how easy it is to point a compass needle in different directions, geophysicists can estimate how much earth’s interior magnetism has changed since records of it were established some 400 years ago. The result for this analysis is shown below.
