Q. Consider the following statements :
Statement I: Scientific studies suggest that a shift is taking place in the Earth’s rotation and axis.
Statement II : Solar flares and associated coronal mass ejections bombarded the Earth’s outermost atmosphere with tremendous amount of energy.
Statement III : As the Earth’s polar ice melts, the water tends to move towards the equator.
Which one of the following is correct in respect of the above statements?
(a) Both Statement II and Statement III are correct and both of them explain Statement I
(b) Both Statement II and Statement III are correct but only one of them explains Statement I
(c) Only one of the Statements II and III is correct and that explains Statement I
(d) Neither Statement II nor Statement III is correct
Correct Answer: (b) Both Statement II and Statement III are correct but only one of them explains Statement I
UPSC Prelims 2025 GS Paper's Solution
Explanation :
– Statement II is correct: powerful solar flares and coronal-mass ejections do indeed slam into and energize Earth’s outer atmosphere (the thermosphere and magnetosphere).
– Statement III is correct: as polar ice melts, the freed water mass is redistributed toward lower latitudes (i.e. toward the equator), altering the planet’s moment of inertia.
Only Statement III provides a mechanism for the observed change in Earth’s rotation‐axis and length‐of‐day (mass moving away from the poles slows Earth’s spin and shifts the instantaneous pole).
Solar storms, although energetic, have only a negligible net effect on the solid‐Earth rotation. Hence both II and III are true, but only III explains Statement I.
