Geomagnetism is the study of the earth’s magnetic behavior. Earth is a giant bar magnet. The geomagnetic field is the magnetic field of the earth. The dipolar origin of this field is inside Earth. From the earth, it extends to outer space, interacting with charged atoms from the sun.
There are various sources of the earth’s magnetic field. A few of these sources include the geomagnetic dynamo, the ionospheric dynamo, the ring current, the tail current, magnetopause current, and field current. Amongst these sources, the geomagnetic source stands out as the most relevant. This is because the other sources exist due to the field it creates. Notwithstanding, the other sources become as effective as the geomagnetic dynamo above the earth’s surface.
The geomagnetic field can be quite variable. The various sources of the geomagnetic field are responsible for these variations when they are disturbed. Here are how some of the sources of the earth’s magnetic field may be disturbed:
Although the earth’s magnetic field exists, it cannot be sensed unless it is measured. The earth’s magnetic field can be measured in a substantial number of ways.
Compass: this is the oldest and most widely known instrument for measuring the earth’s magnetic field or any magnetic field for that matter. When there is a magnetic field, the magnetized needle present in the compass aligns itself in the direction of the magnetic field. The oscillations of the compass needle are used to measure the magnetic field.
Proton-precession Magnetometer: This instrument measures the earth’s magnetic field accurately because of the magnetic and gyroscopic features of protons in a fluid. It is used chiefly for measurements near the earth’s surface.
Fluxgate Magnetometer: it is mainly used in spaceships. It can be used in a spaceship only when the location and orientation of the spaceship relative to the earth is known.
Further Reading: How to Determine North And South Pole of Magnet?
Further Reading: Effects of Earth’s Magnetic Field on Birds
Thank you for reading our article and we hope it can help you to better understand why the earth is a huge magnet. If you want to know more about magnets, we advise you to visit Stanford Magnets for more information.