a. and sb. [f. CO- pref. 2 + SEISMAL.]
A. adj. Relating to the points of simultaneous arrival of an earthquake wave on the earth’s surface; in coseismal line, curve, zone.
1851–9. Mallet, in Adm. Man. Sci. Enq., 361. Upon maps of the country in which the shock was felt, coseismal and meizoseismal curves may be finally laid down.
1877. Le Conte, Elem. Geol., iii. (1879), 124. By drawing a curve through these points we have a coseismal curve.
B. sb. for coseismal line, curve: A line or curve connecting points of simultaneous shock from an earthquake wave.
