Correct Option
The correct option is (a) 1 only.
Explanation
The the geological consequences of Plate Tectonics. The Earth's lithosphere is divided into several tectonic plates that move relative to each other. Their interactions at boundaries-convergent, divergent, and transform-are the primary sources of seismic activity (earthquakes) and volcanism.
Statement-wise Analysis
- Statement 1 is Correct: When tectonic plates brush past one another, it is known as a transform boundary (e.g., the San Andreas Fault). Friction often prevents the plates from sliding smoothly, causing stress to build up. When this stress is released, it causes sudden movements in the Earth's crust, resulting in earthquakes (disturbances).
- Statement 2 is Incorrect: When a plate goes under another due to collision, a process called subduction occurs (convergent boundary). This process causes intense friction and stress accumulation, leading to some of the most powerful earthquakes and volcanic activity. It causes significant disturbance in the crust, contrary to the statement.
- Statement 3 is Incorrect: These disturbances (earthquakes) originate in the lithosphere (the crust and the uppermost solid mantle). They are not confined to the core. The seismic waves generated by the rupture travel through the Earth's layers and cause tremors on the surface.
Key Takeaway
Earthquakes are tremors caused by the sudden release of energy in the Earth's crust resulting from the movement of tectonic plates. These disturbances occur at all plate boundaries (transform, convergent, and divergent) and directly affect the surface.