Q1. What is the term for the movement of tectonic plates causing earthquakes?
- (a) Erosion
- (b) Plate tectonics
- (c) Sedimentation
- (d) Convection
Answer & solution
Answer: (b) Plate tectonics
Plate tectonics is the scientific theory describing the movement of large segments of Earth's lithosphere (tectonic plates) over the asthenosphere. Earthquakes occur primarily at plate boundaries where plates converge (collision/subduction), diverge (rifting), or slide past each other (transform faults). The friction and stress built up at these boundaries is suddenly released as seismic energy — causing earthquakes.
Option 1 (Erosion): Erosion is the wearing away of Earth's surface by wind, water, or ice; not a cause of earthquakes.
Option 3 (Sedimentation): The process of sediment deposition; geological but unrelated to earthquake generation.
Option 4 (Convection): Convection currents in the mantle drive plate movement but are not the direct term for the movement of tectonic plates — plate tectonics is the correct term.