Shifting of North Magnetic Pole
14th Feb, 2019
- Scientists have released a new World Magnetic Model (WMM) to represent the fast drifting of the magnetic North Pole, from the Canadian Arctic to Russia. Since 2000 the rate of moving has jumped from about nine miles (14.5km) to 34 miles (55km) a year.
- A new and updated version of the WMM is released every five years.
What are magnetic poles and how are they different from geographical poles?
- The magnetic North Pole, or South Pole, does not coincide with the geographical North or South Pole.
- Currently, the magnetic North Pole is located somewhere over northern Canada, a fact discovered in 1831 by Sir James Clark Ross.
- Earth behaves like a giant bar magnet characterized by its magnetic north and south poles, which are not static. A compass points towards magnetic north.
- The Earth’s magnetic behaviour is far more complex than that of a simple bar magnet. Its north poles and south poles move around sometimes erratically.
- Over large periods of time, they change their locations significantly, sometimes even interchanging their positions.
- The last time it so happened, with the magnetic North Pole getting somewhere near where the magnetic South Pole currently is, was about 780,000 years ago.
What is the source of magnetic field of earth?
- The origin of Earth’s magnetism lies in its outer core, a more than 2,000-km layer of liquid iron and some other metals like nickel that surrounds the central core, or the innermost part.
- This liquid iron is in constant motion due to Earth’s rotation and various other reasons, and this motion produces a magnetic field.
What causes the current shift?
- The movement of liquid iron and other metals in the outer core of the Earth is known to influence the magnetic field, but this movement is chaotic and turbulent. Though it has not been fully understood but scientists hope that this acceleration in the shifting of magnetic north pole would throw some new insights into the phenomena happening deep inside the Earth’s surface.
- The pole’s recent travels are believed to be caused by the formation of a narrow stream, much like the jet stream in the atmosphere, in the Earth’s liquid outer core.
- The iron-nickel core is so hot that it flows like water, 1,869 miles (3,000km) beneath the surface, creating the magnetic field and dragging it around the planet.
- The north magnetic pole has been caught up in this jet and it’s pushing it rapidly across to Siberia.
- The south magnetic pole is moving far more slowly than the north, because the liquid outer core is moving differently in the southern hemisphere.
Does it mean stronger magnetic field for earth at present?
- Earth’s magnetic field is growing steadily weaker, leading scientists to think it will eventually flip, with the north and south poles changing places like a bar magnet flipping over.
- Researchers know from traces left in rocks that this has happened before, but not in the past 780,000 years.
- Magnetic field’s movement, and the rise and fall in its strength, are all part of its natural behaviour.
- In the long term, the movement of the north magnetic field could become noticeable because it affects where aurora, such as the northern lights, can be seen.
- The aurora is centred on the north magnetic pole in a ring, so as the pole moves, the aurora will follow it.
What are the uses of World Magnetic Model?
- Accurate readings of the magnetic north pole by the WMM are vital for military, surveying and mapping, satellite/antenna tracking, undersea and aircraft navigation, airlines, search-and-rescue operations and other projects circling the North Pole.
- Smartphone and consumer electronics companies also rely on the WMM to provide consumers with accurate compass apps, maps, and GPS services.