Definition of: coseismal

(kō·siz′·məl, -sis′-) adjective
1. Experiencing an earthquake shock simultaneously at all points: a coseismal line or zone.
2. Indicating the progress of an earthquake by a series of connected lines. Also co·seis′·mic,
—noun A line on a map, usually forming a rough oval, and connecting the points at wshich simultaneous earthquake shocks are felt: often called isoseismal. [<CO-¹ + SEISMAL]