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.

---

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

---

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.

---

Other Word Forms

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

Etymology

Origin of seismograph

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

Explanation

A seismograph is an instrument scientists use to measure the strength of an earthquake. Geologists or geophysicists who study earthquakes are called seismologists, and the tool that helps them study the shaking of the ground is called a seismograph or seismometer. It is usually installed at ground level or slightly underground, and it measures how intense an earthquake is. Seismograph comes from the Greek words seismos, "earthquake," and graph, "writing."

Example Sentences

All the decisions, according to The Seismograph, a website deeply sourced in the Vatican, belonged to Francis alone.

From New York Times • Dec. 31, 2022

But the University of Utah Seismograph Stations, which monitors earthquake activity, confirmed in a tweet that no such activity was recorded.

From New York Times • Aug. 13, 2022

The International Registry of Seismograph Stations lists more than 20,000 seismographs on the planet.

From Textbooks • Jan. 1, 2017

Seismic timeline of Marshawn Lynch's touchdown run To the right is the Seismograph from old Kingdome station of the Pacific Northwest Seismic Network.

From Seattle Times • Jan. 10, 2011

Seismograph, sīs′mō-graf, n. an instrument for registering the shocks and concussions of earthquakes, a seismometer.—adjs.

From Chambers's Twentieth Century Dictionary (part 4 of 4: S-Z and supplements) by Various