An earthquake is a sudden and intense shaking of the ground, caused by the movement of tectonic plates beneath the Earth’s surface. These movements can occur due to various geological processes, including the shifting of the earth’s crust along faults, volcanic activity, or the collapse of underground cavities.
Earthquakes can vary in magnitude, which is a measure of the energy released during the seismic event, and intensity, which describes the effects felt on the surface. They can result in significant damage to structures, landscapes, and ecosystems, as well as cause secondary hazards such as tsunamis, landslides, and soil liquefaction.
Seismographs are instruments used to detect and record the vibrations caused by earthquakes, providing valuable data for scientists to study these phenomena. The magnitude of an earthquake is typically measured on the Richter or moment magnitude scales. Earthquake preparedness and engineering practices are essential in areas prone to seismic activity to mitigate potential risks and protect lives and property.
A magnitude 4.7 earthquake occurred off the coast near Seixal, Portugal, causing noticeable tremors in Lisbon and nearby areas. The earthquake's epicenter was 14 kilometers west-southwest of Seixal, at a…