Geography question from JKAS Prelims, 2021 by JKPSC
The gradual change in the direction of the earth's axis is called
Last updated Jun 24, 2026
Correct Answer:
Option C —
Precession
Explanation
Axial Precession is the slow, continuous gravity-induced change in the orientation of Earth's rotational axis. It is often compared to the "wobble" of a spinning top as it slows down.
The Mechanism: This occurs because the Earth is not a perfect sphere but an oblate spheroid (bulging at the equator). The gravitational pull of the Sun and the Moon on this equatorial bulge causes the axis to trace out a large cone in space.
The Timeline: A single complete cycle of precession takes approximately 26,000 years.
The Effect: Precession changes the "North Star" over time. Currently, our axis points toward Polaris, but in about 12,000 years, it will point toward the star Vega.
Why the others are incorrect:
Wandering Polar: This refers to the movement of the magnetic poles or the migration of the rotational poles relative to the Earth's crust over geological time.
Continental Drift: This is the large-scale movement of Earth's continents over the mantle.
Euler's Effect (Free Nutation): This relates to a small shift in the Earth's axis of rotation relative to the Earth's surface, but it is not the "gradual change in direction" in space described by precession.
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.
