The Earth’s Magnetic Field

The Earth behaves as though it has a magnet within it, due to the circulating currents inside its core. The Earth also produces a magnetic field, with the field lines being most concentrated at the poles.

If the Earth contained a large bar magnet, the south pole of that magnet would be near the geographic north, and the north pole of the magnet would be near the geographic south.

  • Although this concept helps with understanding Earth’s magnetic field, there is not actually a magnet in the Earth.

A simplified graphic of Earth with a vertical magnet at its centre, represented by a bar with a red 'N' for the north pole and a blue 'S' for the south pole. Surrounding the Earth are curved lines depicting its magnetic field, flowing in a looped pattern from the north to the south pole. The Earth is depicted with light yellow landmasses on a light blue background, symbolising the oceans.

Navigating the Planet

The Earth’s magnetic field is useful for navigating the planet. A compass, for example, has a magnetic needle that aligns with the Earth’s magnetic field. This needle, when allowed to pivot freely, points to the magnetic north, giving us a consistent reference direction for navigation.

A detailed compass showing cardinal directions. The compass face is white with a clear division for north, south, east, and west, as well as intermediate points like northeast and northwest. It has a surrounding scale from 0 to 360 degrees. The north pointer is a vibrant red, while the south is a deep blue, both coming from the compass's centre.

Because opposite poles attract, the north pole of a compass is drawn to the Earth’s magnetic south pole. Since the Earth’s magnetic south pole is located near its geographic north pole, the north pole of a compass will point towards the geographic north.

A depiction of Earth with its magnetic field represented by blue circular lines with arrows, indicating the direction of the magnetic field. A large magnet, marked with 'N' for North and 'S' for South, runs through the Earth. The Geographic North Pole and Geographic South Pole are also labelled with dashed lines pointing to their respective locations on the planet. The continents are faintly outlined on the Earth's surface.