[sahyz-muh-graf, -grahf, sahys-]
- any of various instruments for measuring and recording the vibrations of earthquakes.
Origin of seismograph
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for seismograph
The seismograph, as you know, was devised to register earthquakes at a distance.The Silent Bullet
Arthur B. Reeve
Really it is doing in a different and often better way what the seismograph does.The Social Gangster
Arthur B. Reeve
In order to get a record of the successive shocks another form of apparatus must be employed, a form known as a seismograph.The Wonder Book of Volcanoes and Earthquakes
Edwin J. Houston
But even at noon the disturbance had not subsided, as slight shocks are recorded at frequent intervals on the seismograph.
The seismograph of to-day, however, has reached a stage of perfection where close approximations are obtained in the records made.
- an instrument that registers and records the features of earthquakes. A seismogram (ˈsaɪzməˌɡræm) is the record from such an instrumentAlso called: seismometer
Word Origin and History for seismograph
Online Etymology Dictionary, © 2010 Douglas Harper
- An instrument that detects and records vibrations and movements in the Earth, especially during an earthquake. Most seismographs employ a pendulum mounted within a rigid framework and connected to a mechanical, optical, or electromagnetic recording device. When the Earth vibrates or shakes, inertia keeps the pendulum steady with respect to the movements of the frame, producing a graphic record of the duration and intensity of the Earth's movements. Separate instruments are needed to record the north-south horizontal, east-west horizontal, and vertical components of a tremor. By comparing the records produced by seismographs located in three or more locations across the Earth, the location and strength of an earthquake can be determined.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.