Brain Booster for UPSC & State PCS Examination (Topic: Magnetic Field Weakening)

Brain Booster for UPSC & State PCS Examination


Brain Booster for UPSC & State PCS Examination


Topic: Magnetic Field Weakening

Magnetic Field Weakening

Why in News?

  • The magnetic field of the Earth between Africa and South America is weakening, causing problems for satellites and spacecraft.
  • The data gathered by the European Space Agency’s (ESA) swarm of satellites reveals that the area of the anomaly dropped in strength by over 8 percent between 1970 and 2020.
  • The ESA has termed the phenomenon of this change of geomagnetic field or the surface magnetic field as 'South Atlantic Anomaly' (SAA).
  • SAA is a region of reduced magnetic intensity where the inner radiation belt makes its closest approach to the Earth's surface. Satellites in low-Earth orbit pass through the SAA periodically, exposing them to several minutes of strong radiation each time, creating problems for scientific instruments, human safety, and single event upsets.

Earth's Magnetic Field

  • The magnetic field of Earth, also known as the geomagnetic field, extends from the Earth's outer core and exerts a force on the charged particles coming from the Sun, protection us from the cosmic radiations.
  • Earth's magnetic field, which exists due to metal and liquid outer core about 3,000 km below the surface, creates electric currents that generate and change our electromagnetic fields.
  • The rotation of the Earth creates movements inside the liquid outer core which gives rise to the geomagnetic field.

Importance of Earth's Magnetic Field

  • It protects from the cosmic radiations and solar winds that are harmful to us.
  • The surface magnetic field, which spans around tens and thousands of kilometers away from the Earth, aids the communication of satellites and spacecraft.
  • A compass works the way it does because of the Earth’s magnetic field.
  • The geomagnetic field forms the planet’s magnetosphere.

Possible Reasons of Weakening of Magnetic Field

  • A team from Leeds University said the drift of the North Pole is explained by the competition of two magnetic "blobs" on the edge of the Earth's outer core. Changes in the flow of molten material in the Earth’s interior have changed the strength of the negative magnetic flux.
  • This change in the pattern of flow has weakened the patch under Canada and ever so slightly increased the strength of the patch under Siberia. This is why the North Pole has left its historic position over the Canadian Arctic and crossed over the International Date Line.
  • Another possible reason, as per the ESA, could be that the Earth’s magnetic field is reversing i.e. the North and the South Poles may be switching. Such geomagnetic reversals happen roughly every 2,50,000 years and given the last one took place 7,80,000 years ago, it was long overdue.

Effects of Weakening of Earth’s Magnetic Field

  • The magnetic field of Earth protects the life of Earth from the harmful cosmic radiation and charged particles emitted from the Sun.
  • Birds, turtles and other creatures also use the magnetic field of Earth to navigate.
  • In effect, the navigation systems and mapping functions in smartphones may be affected.
  • If a reversal takes place, the repercussions could be significant and could cause major issues for telecommunications and satellite systems. Certain mobile phones and satellites may stop working.

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