Final answer:
Earth's magnetic field is generated by the circulation of liquid metallic substances in the core, forming electric currents and a magnetic field similar to a giant bar magnet. This magnetism creates the magnetosphere, which protects Earth by trapping charged particles. The Earth's magnetic poles are dynamic and shift slightly over time.
Step-by-step explanation:
Earth's magnetic field is generated in the core, which is made of liquid metallic substances that is constantly moving. These liquid metals, like iron, flow and create circulating electric currents, subsequently producing a magnetic field. This acts much like a giant bar magnet with magnetic poles that align closely with Earth's rotational poles. Moreover, this magnetic field extends into space, forming the magnetosphere, where it captures charged particles. Essential concepts in physics suggest that a magnetic field is generated either by magnetic dipoles or moving charged particles, which is precisely what occurs in Earth's outer core.
The dynamics within Earth's core create electric currents and hence a magnetic field, which is not only critical for navigation using a compass but also protects our planet by trapping charged particles in the magnetosphere. The geographical and magnetic North Poles are not identical, with the magnetic poles shifting slightly over time, indicating the complexity and dynamism of Earth's magnetism.