MAGNETIC NORTH POLE

TAG: GS-1: GEOGRAPHY

CONTEXT: The magnetic north pole is, reportedly, drifting fast away from the Canadian Arctic and towards Russia.

EXPLANATION:

What are the poles on earth?

• • The Earth has two pairs of north and south poles.
  • The geographic poles are defined by the axis around which the planet rotates, and these are fixed.
  • The Earth behaves much like a giant bar magnet and this behaviour defines its magnetic north and south poles.
  • But these are not static as the geographic poles.

What causes the magnetic field?

• • The origin of Earth’s magnetism lies in its outer core which is a more than 2,000-km layer that surrounds the central core or the innermost part.
  • The outer core is comprised of liquid iron and some other metals like nickel.
  • This liquid iron is in constant motion due to Earth’s rotation and various other reasons, and this motion produces a magnetic field.

What is the recent development?

• • In 1831, it was discovered that the magnetic north pole was located somewhere over northern Canada.
  • Since then, the magnetic north pole has been moving hundreds of miles across the Canadian Arctic towards Russia.
  • It has now been found that the pace of this movement has suddenly increased, quite significantly.
  • It has been moving from about 14-15 km per year till the 1990s to about 55 km per year in the last few years.
  • This, now, led to scientists updating the World Magnetic Model (WMM) that tracks this movement.
  • Every 5 years, a new and updated version of the WMM is released; the current update is a year ahead of the schedule.
  • The faster movement of the magnetic north pole had made WMM so inaccurate that it was about to exceed the acceptable limit for navigational errors.

How have the positions changed?

• • The constant motion is the reason for the magnetic poles to not coincide with the geographical poles.
  • It is also why the Earth’s magnetic behaviour is far more complex than that of a simple bar magnet.
  • Resultantly, the magnetic north poles and south poles move around sometimes erratically.
  • Over large periods of time, they change their locations significantly, sometimes even interchanging their positions.
  • Around 780,000 years ago, the magnetic north pole was getting somewhere near where the magnetic south pole currently is.
  • But this time period of shift in positions is not fixed.

What is the significance?

• • Given the extremely hot temperatures, the phenomena happening inside the earth can only be studied indirectly or through computer modelling.
  • So, the causes for the fast movement are uncertain yet.
  • But the shifting of magnetic north pole would throw some new insights into the phenomena happening deep inside the Earth’s surface.

Source: https://pib.gov.in/PressReleasePage.aspx?PRID=2075285