Scientists have imagined Earth to be a massive magnetic dipole.
A magnetic dipole is a pair of equal and opposite poles separated by a small distance. In a bar magnet, the north and south poles are separated by certain distances, making it a dipole.
A magnetic dipole
The location of the Earth's magnetic poles, on the other hand, is not well known on Earth.
The imaginary magnet within the Earth's core has a magnetic south pole near the geographic north pole and the magnetic north pole near the geographic south pole.
Magnetic lines of Earth
An imaginary line called the magnetic axis connects these two magnetic poles.
The magnetic axis bisects the geographic north pole at the north geomagnetic pole, also known as the northern magnetic pole, and geographic south pole at the south geomagnetic pole, also known as the southern magnetic pole.
The magnetic and the geographical axis or the axis of rotation never coincide with each other. The angle of inclination of Earth's magnetic axis is about \(10°\) to \(15°\) with the geographical axis of the Earth.
Factors causing Earth's magnetism:
Even now, the reason for Earth's magnetism is unclear. However, some significant factors may be the cause of the Earth's magnetism. They are,
- Magnetic substances in the Earth's masses
- Sun's radiations
- Action of the Moon
It is assumed that the magnetic field of Earth is generated by a molten charged metallic fluid within the Earth's crust or surface. Earth's core has a radius of around \(3500\ km\) compared to the Earth's radius of \(6400\ km\).
Layers of Earth