Final answer:
An earthquake occurs when energy stored in the Earth's crust is released, often due to movement along fault zones. The violent release of energy causes seismic waves that can result in significant damage, depending on their amplitude. Human activities, such as fossil fuel extraction, can also induce earthquakes.
Step-by-step explanation:
An earthquake is a phenomenon where stored energy in the Earth's crust is released, typically along fault lines where tectonic plates meet. This energy release sends seismic waves radiating through the Earth's interior and along its surface, causing the ground to shake. Earthquakes can result from various factors, such as the slow creeping motion of tectonic plates that build up stresses over time. When these stresses become too great, they are suddenly released in violent slippages along fault zones.
The severity of an earthquake can vary significantly, with the most powerful ones capable of causing extensive damage, toppling buildings and infrastructure, and even causing natural disasters such as tsunamis when they occur under the ocean. The energy of a seismic wave is directly related to its amplitude; waves with larger amplitude displace more ground and cause more destruction. Over time, as seismic waves move away from the earthquake's source, their amplitude decreases, reducing the potential for damage at greater distances.
It is important to note that while earthquakes happen naturally, human activities, such as traditional oil and gas production, can also contribute to the occurrence of earthquakes. These anthropogenic earthquakes, however, generally have different characteristics compared to natural tectonic earthquakes. In addition, buildings that experience the same frequency of vibration as their natural frequency can resonate, intensifying the effects of an earthquake.