seismograph

American  

[sahyz-muh-graf, -grahf, sahys-] / ˈsaɪz məˌgræf, -ˌgrɑf, ˈsaɪs- /

noun

1. any of various instruments for measuring and recording the vibrations of earthquakes.

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seismograph British  

/ saɪzˈmɒɡrəfə, ˈsaɪzməˌɡrɑːf, ˌsaɪzməˈɡræfɪk, -ˌɡræf /

noun

1. Also called: seismometer.  an instrument that registers and records the features of earthquakes. A seismogram ( ˈsaɪzməˌɡræm ) is the record from such an instrument

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seismograph Scientific  

/ sīz′mə-grăf′ /

1. 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.

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Other Word Forms

• seismographer noun
• seismographic adjective
• seismographical adjective
• seismography noun

Etymology

Origin of seismograph

First recorded in 1855–60; seismo- + -graph

Example Sentences

They then analyze the simulated wave patterns at seismograph locations and compare them with real seismograms, which are graphical records of ground motion from actual earthquakes.

From Science Daily

After the fact, seismologists study measurements of the ground’s movement taken by seismographs and evaluate the damage done by the quake to decide what magnitude to assign to the event.

From Literature

When a patient is having a seizure, these lines jump up and down dramatically like a seismograph during an earthquake -- a signal that is easy to recognize.

From Science Daily

When the edge of two tectonic plates shift to produce an earthquake, the seismic waves it emits are measured by seismographs all over the world.

From Salon

These anomalies can be observed when seismographs pick up signals from earthquakes.

From Science Daily