What phenomenon is caused by the movement of rocks beneath the Earth's surface?

The correct answer is an earthquake, which occurs due to the movement of rocks beneath the Earth's surface, primarily along faults. When stress builds up in the Earth's crust—caused by tectonic plates colliding, sliding past each other, or pulling apart—it can lead to a sudden release of energy. This release produces seismic waves, which we feel as shaking on the surface.

Earthquakes can vary in magnitude and can be strong enough to cause significant destruction, depending on their depth, proximity to populated areas, and geological conditions. Understanding earthquakes is crucial for disaster preparedness and mitigation strategies in regions prone to seismic activity.

The other options refer to different geological phenomena. For example, volcanos are formed by molten rock coming to the surface, tsunamis are large ocean waves typically triggered by underwater disturbances like earthquakes or volcanic eruptions, and landslides involve the movement of rock and soil down slopes, often due to gravity, but not directly related to the tectonic movements that cause earthquakes. These distinctions help clarify why earthquakes specifically result from the movement of rocks under the Earth's surface.