An apparatus for registering the shocks and undulatory motions of earthquakes.
An instrument for magnifying and recording the motions of the Earth's surface that are caused by seismic waves.
A device that records natural or manmade vibrations from the earth. Geologists read what it has recorded to evaluate the oil potential of underground formations.
A graph that is produced by a seismometer, showing the magnitude and length of earth movements. siesmic earthquake Richter
A sensitive instrument that can detect, amplify, and record ground vibrations too small to be perceived by human beings. (See also accelerograph.)
An instrument that measures and may furnish a permanent record of earthborne vibrations and air overpressure induced by blasting.
A machine for measuring the intensity of earthquakes by recording the seismic waves that they generate.
An instrument that records seismic waves; that is, vibrations of the earth.
An instrument that detects, records, and measures the various waves produced by an earthquake. Also called seismometer, seismic detector, geophone.
an instrument that detects and measures Earth movement associated with earthquakes.
instrument for recording vibrations, most commonly employed for recording earth vibrations during earthquakes.
a measuring instrument for detecting and measuring the intensity and direction and duration of movements of the ground (as an earthquake)
a device that detects and records elastic waves (seismic waves) traveling through the Earth from either a natural source--an earthquake--or an artificial one, such as a mining or construction blast
a device that records earthquake waves
a device used for recording earth tremors
a machine that records the ground vibrations during a quake
an instrument that measures and records elastic ground vibrations called seismic waves that are generated by earthquakes and man-made explosions
an instrument that records these vibrations
an instrument that records the shaking of the
an instrument used to measure and record ground vibration caused by explosions and earthquake shock waves
a pendulum, consisting of a suspended heavy weight attached to a recording device - traditionally a pen touching the surface of a paper chart on a rotating drum
a tool used to record earthquake and volcano activity
a tool used to record the time at which the underground rocks return the waves to the surface
An instrument that is used to record vibrations of the Earth.
Instrument for automatically detecting and recording the intensity, direction, and duration of a movement of the ground, especially of an earthquake.
An instrument that registers the occurrence of an earthquake and the time it occurred as a written record.
An instrument that detects and records the vibrations of Earth.
an instrument used to detect and measure seismic waves.
a device that records vibrations from the earth or which records shock waves set off by explosions in shot holes and picked up by geophones.
An instrument used to measure the shaking caused by an earthquake.
A very sensitive instrument used to record and measure earthquakes. During an earthquake, vibrations initiated by fracturing of the earth's crust radiate outward from the point of fracture and are detected by seismographs. The visual record produced is called a "seismogram".
a device for measuring and recording vibrations from earthquakes.
An instrument that records the motions of the Earth, especially earthquakes.
An instrument that detects and records vibrations caused by earthquake shock waves
An instrument that can record the ground motion from an earthquake.
An instrument used to detect and measure earthquakes. It senses and records the vibrations that radiate out from the earthquake focus.
Apparatus used to measure and record vibrations in the earth. It is used to detect possible oil-bearing structures.
A scientific instrument that detects and records vibrations (seismic waves) produced by earthquakes.
an instrument used to record seismic waves. Click here to see an animation
An instrument that measures and records the Earth's vibrations. The seismograph indicated that an earthquake was coming.
An instrument that records the motions of the Earth's surface.
A seismograph is a device that records and measures seismic waves (vibrations in the Earth), like those from earthquakes.
An instrument that detects, magnifies, and records vibrations of the Earth, especially earthquakes
an apparatus to measure and record ground movements as produced by natural or man-made causes.
We record earthquakes through the use of seismographs. Seismographs are instruments that create an electrical signal when the ground moves. By comparing the signal from many seismographs at different locations we can determine if an earthquake occurred and by timing the waves that travel from the earthquake, determine where and when it occurred.
Photo courtesy of USGS, National Earthquake Information Center
An instrument used to measure and record earthquake vibrations and other earth tremors. It consists essentially of a heavy pendulum hung so that it can swing freely in one direction. A pen is attached to the end of the pendulum so that the pendulum's motion, relative to a recorder fixed solidly to the earth, may be determined. A seismological observatory requires three seismographs in order to measure the three component directions of the tremors and to fix approximately their origin. A study of the records of sensitive seismographs has shown that some of the tremors may be attributed to oceanographic and atmospheric phenomena. See microseism.