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
This phenomenon, specifically known as Axial Precession, describes the slow, continuous gravity-induced change in the orientation of Earth's rotational axis.
Why it happens
Much like a spinning toy top that wobbles when its speed decreases, Earth experiences a similar "wobble." This is primarily caused by the gravitational pull of the Moon and the Sun on Earth's equatorial bulge (the fact that Earth is slightly thicker at the equator than at the poles).
Key Characteristics
The Cycle: It takes approximately 26,000 years for the Earth to complete one full circle of precession.
The North Star: Because the axis is moving, the "North Star" changes over millennia. Currently, our North Star is Polaris, but in about 12,000 years, the axis will point toward the star Vega.
Equinoxes: This movement is also responsible for the "Precession of the Equinoxes," where the positions of the equinoxes slowly drift westward along the ecliptic.
Distinguishing the other options:
Wandering Polar: Refers to the movement of the magnetic or geographic poles across the Earth's surface over geological time, often linked to tectonic shifts.
Continental Drift: The movement of Earth's continents relative to each other across the ocean bed.
Euler's Effect (Chandler Wobble): A small deviation in the Earth's axis of rotation relative to the solid Earth, occurring over much shorter periods (about 433 days).
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.
