An earthquake can be a common occurrence but the varying intensities and magnitudes make each tremor unique. For instance, a slight earthquake can be referred to as a tremor, while a larger one can be considered a seismic activity. Similarly, if the earthquake happened underwater, it could be labeled as an underwater quake. Often, it's called a regular or a typical occurrence if it happens within known fault lines while a quake that happens in an unknown area can be dubbed an unanticipated earthquake. Other synonyms for a normal event earthquake include temblor, earth tremor, ground shake, seismic disturbance, and shock wave. Regardless of the term used, earthquakes are natural phenomena that should be taken seriously.