1.
hypocenter; seismic focus
The underground point where an earthquake originates, as distinct from the epicenter (⟦震央→震央:24851_shinou⟧), the point on the surface directly above it. A key term in earthquake-related news and information.
2.
source; origin; root cause
Figuratively, the origin or source of trouble, conflict, or a problem.
Usage
震源 combines 震 (quake, tremor) and 源 (source, origin). Strictly speaking, 震源 is the hypocenter, the underground point of origin, while 震央 is the epicenter, the point on the surface directly above it. 震源地 names the area on the surface where the quake originated; news reports give it as a place name (e.g. 震源地は〜沖).
Common collocations
Similar words
震源地 is the surface area named as the quake's location; 震源 is the underground point itself and is also the form used in figurative senses.