Part of: GS-Prelims and GS-I – Geographical phenomenon
In News:
As per the reports, the magnetic field around the earth, on an average, has lost almost 10% of its strength over the last two centuries.
The magnetic field of the earth protects us from the solar radiation.
Key takeaways
A rapid shrink has been observed in the South Atlantic Anomaly (SAA).
One most speculated reason behind this is that there is a chance that the time for Earth’s pole reversal is approaching.
Pole reversal happens when the north and south magnetic poles flip.
This flip does not occur immediately or suddenly.
It takes place over centuries and while it is taking place, there would be multiple north and south magnetic poles during this period, all around the planet.
This is not the first time for the pole reversal to take place.
These reversals take place roughly every 250,000 years.
This is not going to affect or alarm the general public.
However, It is causing technical difficulties for various satellites and spacecrafts.
As the magnetic field becomes weaker, charged particles from the cosmos can penetrate through to the altitudes at which low-Earth orbiting satellites fly.
Important value additions
South Atlantic Anomaly (SAA)
SAA is a stretch between Africa and South America.
It is an area where the Earth’s inner Van Allen radiation belt comes closest to the Earth’s surface.
The SAA is the near-Earth region where the Earth’s magnetic field is weakest relative to an idealized Earth-centered dipole field.
A Van Allen radiation belt
It is a zone of energetic charged particles, most of which originate from the solar wind, that are captured by and held around a planet by that planet’s magnetic field.
Earth has two such belts and sometimes others may be temporarily created.
