A line on a map joining points of equal seismic intensity produced by an earthquake. Also know as an isoseismal line.(noun)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "isoseismal" in a sentence
"The isoseismal 6 is 105 miles long, 87 miles wide, and contains 7,300 square miles; and the isoseismal 5, 157 miles long, 143 miles wide, and about 17,000 square miles in area."
"The resistance offered by the Sierra Nevada to the propagation of the earth-waves is shown in the former map by the approximation of the first and second isoseismals at the east end, and in the latter by the great bay in the third isoseismal line."
"Again, in slight earthquakes, such as the Cornwall earthquake of April 1, 1898,  the curves of equal sound intensity, while their axes are parallel to those of the isoseismal lines, are displaced laterally with respect to these curves, owing to the arrival of the strongest sound-vibrations from the upper margin of an inclined seismic focus."