Fusakichi Omori was a pioneer Japanese seismologist, second chairman of seismology at Tokyo Imperial University and president of the Japanese Imperial Earthquake Investigation Committee. Omori is also known for his observation describing the aftershock rate of earthquakes, now known as Omori's law.

Seismology is the scientific study of earthquakes and the generation and propagation of elastic waves through the Earth or other planetary bodies. It also includes studies of earthquake environmental effects such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, glacial, fluvial, oceanic microseism, atmospheric, and artificial processes such as explosions and human activities. A related field that uses geology to infer information regarding past earthquakes is paleoseismology. A recording of Earth motion as a function of time, created by a seismograph is called a seismogram. A seismologist is a scientist works in basic or applied seismology.