seismograph

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seismograph

an instrument that registers and records the features of earthquakes. A seismogram is the record from such an instrument

seismograph

(sÿz -mŏ-graf, -grahf) An instrument used in seismology to detect and record the passage of seismic waves, normally by making a continuous recording of the position of a suspended mass in relation to a frame fixed to the ground.

Seismograph

an instrument that records oscillations of the ground caused by seismic waves.

Figure 1. Diagram of a seismograph: (1) seismometer weight, (2) damper (device to attenuate the free oscillations of the weight), (3) device for converting the movement of the weight into an electrical signal, (4) filter-amplifier, (5)recorder

A seismograph (Figure 1) consists of a seismometer—an instrument that receives the seismic signal—and a recording device. The basic part of the seismometer is a weight connected with the case of the instrument by elastic couplings, for example, a pendulum. The case of the instrument is rigidly fixed to the object being studied. When the object oscillates, inertia causes the weight to move relative to the case. In most modern seismometers, this movement is converted into an electrical signal, which is recorded, usually in analogue form, by a mechanical, photographic, or magnetic recorder. Coded digital recording is sometimes used to increase the dynamic range and for convenience in subsequent computer processing.

There are also simpler seismographs, in which the movement of the seismometer weight is magnified mechanically or optically and is recorded by a mechanical or photographic recorder.

D. P. KIRNOS

seismograph

[′sīz·mə‚graf]

(engineering)

An instrument that records vibrations in the earth, especially earthquakes.

References in periodicals archive ?

The mass movements of large crowds of people can be detected by seismographs, but they do not trigger earthquakes.

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"My seismograph is my dropleaf secretary,'' he said.

Earthquakes drop in; Rumbly visitors just keep coming back

RMS is determined by the magnitude of this energy using seismographs to measure the logarithm of the seismic waves' amplitude.

Earthquake warning..

It operated like a horizontal pendulum, but, like all the wonderful creations of a Black Country shed, the world's first seismograph was made from whatever was lying around.

Seismograph invention was a Shaw thing; Chris Upton discovers how one Black Country man shook the world with a new machine created in his garden shed

The tip of the cable is equipped with a node (enhanced branching device) that features a broadband seismograph, acceleration seismograph, tsunami pressure gauge, conductivity temperature and depth-sensor and underwater microphone.

NEC Announces Completion of First Integrated Ocean Observation System for Taiwan

To see the volcano's activity as soon as possible, the agency installed three seismographs at a height of 2,000 meters at Batu Palano area and a digital analog at a height of 1,500 meters at Lasi area.

Mount Marapi Erupts Twice in West Sumatra Province

The end of the cable is equipped with a node (enhanced branching device) that features a broadband seismograph, acceleration seismograph, tsunami pressure gauge, conductivity temperature and depth-sensor and underwater microphone.

NEC Announces First Integrated Ocean Observation System for Taiwan; Taiwan Central Weather Bureau to Observe Taiwan Eastern Sea

2 : to show a measurement of <A seismograph records the strength of earthquakes.>

record [1]

With a magnitude of between 9.1 and 9.3, it is the second-largest earthquake ever recorded on a seismograph. It had the longest duration of faulting ever observed, between eight and 10 minutes, causing the entire planet to vibrate.

Second-largest earthquake

hears somebody ask, like a tremble on a seismograph, but you can't

Herb Parker Feels Like Dancing

DEVASTATION Injured pupil is pulled from the rubble in Dujiangyan yesterday; TERROR Primary school pupils cower under desks; SUFFERING Woman with injured son; CARNAGE Cars in debris in Dujiangyan; READING Seismograph print-out of quake; DISASTER AREA

QUAKE ENTOMBS 900 SCHOOLKIDS; Death toll may hit 10,000 7.8 shock is worst in 30yrs Cities left without power

Sure, their date at the CIA last night might not have nudged the cultural seismograph off the Richter Scale but, you knowwhat, for lovers of great music this was one of the highlights not just of this year, but any year.