seismology

[Gr. seismos =an earthquake; suff. -ology.] Physics: The study of earthquakes. Prof. Milne ( Earthquakes , Introd.) suggests that in addition to what are generally known as earthquakes, seismology should investigate: (1) Earth-tremors, or minute movements which escape attention by the smallne of their amplitude; (2) Earth-pulsations, or movements which are overlooked on account of the length of their period; and (3) Earth-oscillations, or slow and quiet changes in the relative level of the sea and land, which geologists speak of as elevations or subsidences. Although seismology can scarcely be said to have existed before the early part of the nineteenth century, it has a rapidly growing bibliography, is accumulating a store of facts and observations on which generalizations may be based, and Prof. Milne is sanguine that earthquake-warnings in countries subject to seismic disturbances will be as common and as trustworthy as the storm-warnings at our seaports. (See also Brit. A oc. Report , 1858.) "Another great impetus which observational seismology received was Mr. Mallet's report upon the Neapolitan earthquake of 1857."-J. Milne: Earthquakes, p. 8. sin, as; expect, Xenophon. exist. ph = f. seismometer