from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Relating to or designating a line connecting the points on a map that indicate the places simultaneously affected by an earthquake shock.
- n. A coseismal line.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Of or pertaining to a line on a map connecting places simultaneously affected by a seismic event.
from The Century Dictionary and Cyclopedia
- The term used by Mallet to designate the curve or line along which a wave of earthquake-shock “simultaneously [synchronously] reaches the earth's surface”; the crest of a wave of shock. See homoseismal, isochrone, isoseismal.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. being where earthquake waves arrive simultaneously
Sorry, no etymologies found.
If, however, the number of observations is large for the size of the disturbed area, the construction of coseismal lines may define approximately the position of the epicentre.
There is thus an apparent increase in the velocity with the distance, but the accuracy of the coseismal lines is unequal to establishing this as a fact.
With evidence so abundant, a new method of drawing coseismal lines becomes possible.
The coseismal lines obtained in this manner are represented by the continuous curves in Fig. 62.
It will be seen that the coseismal lines are elongated in the same direction as the isoseismals, but to a less extent, and this no doubt is due to the fact that the epoch selected by the majority of observers was one not far from, and slightly preceding, that of the maximum intensity of the shock.
In the Hereford earthquake of 1896, the centre of the innermost coseismal line (Fig. 62) is close to the region lying between the two epicentres.
Owing, however, to the inevitable inaccuracy of all the time-records, these different zones intrude on one another, and the coseismal lines have therefore to be drawn about half-way through the overlapping regions, special weight being attributed to the apparently more accurate observations.
The curves separating these zones would be coseismal lines corresponding to the times 5. 32-1/2, 5. 33-1/2, and