A seismometer is the device used to measure earthquakes and other seismic activities. It detects and records the vibrations and movements of the Earth's crust caused by tectonic shifts, volcanic activity, or human-made explosions. Seismometers work by sensing the ground's motion and translating it into a readable format, often producing graphical representations known as seismographs. This data is vital for understanding earthquake patterns, assessing risks, and informing safety measures in earthquake-prone regions. Seismometers are crucial tools in geology and earthquake engineering, contributing to advancements in predicting and responding to seismic events.