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?
Answer & explanation
Answer: (b) Both Statement II and Statement III are correct but only one of them explains Statement I
Both Statement II and Statement III are true, but only Statement III explains Statement I. Melting polar ice moves mass from the poles towards the equatorial ocean, and such shifts of mass change Earth's rotation and axis. A solar storm heats the upper atmosphere but does not shift the planet's mass, so it cannot explain a change in rotation or axis.
- ✓ I NASA-funded studies show Earth's spin axis drifts (polar motion) and its rotation slows, as mass is redistributed on and within the planet.
- ✓ II Solar flares and coronal mass ejections do hit Earth's upper atmosphere with charged particles and energy and can heat it. This is a space-weather effect and does not move Earth's mass, so it does not explain Statement I.
- ✓ III Faster melting of ice sheets has shifted mass from the poles towards the equatorial ocean. This redistribution of mass is the cause of the change in rotation and axis, so it explains Statement I.
Remember · Ice melt shifts mass from the poles to the equatorial oceans, changing Earth's spin axis and lengthening the day; solar storms only affect the upper atmosphere.
Sources
- NASA-Funded Studies Explain How Climate Is Changing Earth’s Rotation (NASA, Internet Archive copy) ↗ “In recent decades, the faster melting of ice sheets has shifted mass from the poles toward the equatorial ocean. … These resulting shifts in mass cause the planet to wobble as it spins and its axis to shift location — a phenomenon called polar motion.”
- Solar Storms and Flares (NASA Science, Internet Archive copy) ↗ “temporarily heat up Earth’s upper atmosphere, causing it to swell and increase drag on some Earth-orbiting satellites, which makes the satellites slow down and lose altitude.”
Question and answer: UPSC's official GS Paper I (2025, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·