Science Olympiad Dynamic Planet Practice Test

What leads to the release of stored energy in the context of an earthquake?

1. The build-up of stress on the fault surface

2. A sudden drop in tectonic activity

3. Increase in the Earth's temperature

4. Global seismic wave interference

The correct answer is: The build-up of stress on the fault surface

The release of stored energy during an earthquake primarily occurs due to the build-up of stress on the fault surface. Over time, tectonic forces cause stress to accumulate as the Earth's plates move against each other along fault lines. When the stress exceeds the strength of the rocks that form the fault, it leads to a sudden release of energy. This energy release results in the seismic waves that we feel as an earthquake. The other options do not accurately explain the mechanism behind earthquake energy release. A sudden drop in tectonic activity would likely lead to a period of calm rather than an earthquake, as there would be less movement contributing to stress accumulation. An increase in the Earth's temperature does not directly cause earthquakes; rather, it can influence geological processes over long timescales. Lastly, global seismic wave interference refers to the interaction of seismic waves from multiple earthquakes, which doesn’t contribute to the stress release that characterizes an earthquake event.