Earth magnetism is the property of earth behaving like a dynamo and showing magnetic property just like that of a magnetic bar. There are various theories behind this property.
There is no valid reason for the cause of earth’s magnetism or why earth has giant magnetic field but there are some theory related to earth’s magnetic field which helps us to understand that why earth behaves as a giant magnet.
- It is believed that the magnetic field of earth is due to dynamo effect. Dynamo effect is caused by the motion of metallic fluids in the outer core of the earth which results in electric current. It is because of this electric current that the earth has its own magnetic field lines.
- Another theory suggests that the rotation of earth in its own axis produces strong electric current since the outer layers of earth is ionized. As a result of which when the earth rotates, there is a movement of charged ions, which in return produces electric current.