When the rocky tectonic plates that form Earth’s crust move suddenly, large waves of energy spread out, causing the ground to shake. This is an earthquake. Some earthquakes are fairly gentle and may even go unnoticed, but others can bring terrible destruction.

Sometimes an earthquake has foreshocks. These are smaller earthquakes that happen in the same place as the larger earthquake that follows. Scientists can’t tell that an earthquake is a foreshock until the larger earthquake happens. The largest, main earthquake is called the mainshock. Mainshocks always have aftershocks that follow. These are smaller earthquakes that occur afterwards in the same place as the mainshock. Depending on the size of the mainshock, aftershocks can continue for weeks, months, and even years after the mainshock!


Picture Credit : Google