"Aftershock" is a term used to describe smaller earthquakes that occur in the same area after a larger seismic event. These aftershocks can happen days, weeks, or even months after the main quake, gradually decreasing in intensity. They are caused by the Earth's crust adjusting to the changes in stress and strain following the initial earthquake. In the context of seismic activity, aftershocks can pose additional risks to structures and communities already affected by the main earthquake. Understanding aftershocks is crucial for emergency response and recovery efforts, as they can complicate rescue operations and hinder rebuilding efforts in areas impacted by the initial quake, such as those affected by the San Andreas Fault.