<P> In its most general sense , the word earthquake is used to describe any seismic event -- whether natural or caused by humans -- that generates seismic waves . Earthquakes are caused mostly by rupture of geological faults , but also by other events such as volcanic activity , landslides , mine blasts , and nuclear tests . An earthquake 's point of initial rupture is called its focus or hypocenter . The epicenter is the point at ground level directly above the hypocenter . </P>
<P> In its most general sense , the word earthquake is used to describe any seismic event -- whether natural or caused by humans -- that generates seismic waves . Earthquakes are caused mostly by rupture of geological faults , but also by other events such as volcanic activity , landslides , mine blasts , and nuclear tests . An earthquake 's point of initial rupture is called its focus or hypocenter . The epicenter is the point at ground level directly above the hypocenter . </P>
what do you call the origin of an earthquake
what do you call the origin of an earthquake
focus hypocenter
focus hypocenter