What Is A Seismograph? (with Picture) ~ OnNews

How a Seismograph Works. 727 909 просмотров 727 тыс. просмотров. 3-component Seismograms—Capturing the motion of an earthquake.The mass tends not to move because of its inertia, and by measuring the motion between the frame and the mass, the motion of the ground can be The output of a digital seismographs can be simply input to a computer. They present the data in standard digital forms (often "SE2" over ethernet).Scientists use a machine called a seismograph to measure the motion of the ground during an earthquake. When the ground moves during an earthquake, the frame moves back and forth along with the ground. The heavy weight, however, is not connected directly to the ground, and it wants to...Working of a seismograph. A seismometer consists of a mass hanged to the frame with a fixed base. The seismograph is designed in such a way that when the earthquake happens then, mass remains fix (Due to inertia) but base moves due to the movement of the earth surface.A seismograph tells you how fast the ground moves, and writes it down for you. A seismograph is securely mounted onto the surface of the earth so that when the earth shakes, the entire unit shakes with it, EXCEPT for the mass on the spring which has inertia, and remains in the same place.

Seismometer - Wikipedia, the free encyclopedia

Official website of SEIS seismometer, main instrument of Mars InSight mission. The pen touches a roll of paper wound around a rotating drum. This is known as a seismograph, an instrument which The seismometer provides data as a seismogram, which is a recording of the magnitude of ground...A seismograph, in its simplest form, is built with a free-hanging needle that moves like a pendulum over a seismogram. When the ground begins to move, the needle remains stationary as the seismogram below it moves back and forth with the motion of the earth during the earthquake.A seismograph consists of a pendulum mounted on a support base. The pendulum in turn is connected to a recorder, such as an ink pen. When the ground vibrates, the pendulum remains still while the recorder moves, thus creating a record of the earth's movement.History of seismographs How to make a seismograph Interpreting your seismograph Modern day seismometers Related websites. To make a seismograph, you need to get one thing to move with the earth as it shakes, and something else to stay as still as possible relative to the earth.

Shaky Science: Build a Seismograph - Scientific American

Definition of a Seismograph. Seismic waves are the vibrations from earthquakes that travel through When an earthquake hit, the mercury would move and make electrical contact that stopped a clock and started a Because of the logarithmic basis of the scale, each whole-number increase in magnitude...The seismographs today are electronic and they mainly consist of a drum with paper on it, a bar with a hinge on it (either on one, or both sides), a weight, and a pen. When an earthquake occurs everything inside the seismograph moves except for the weight with the pen placed on it. As the drum and...Seismographs are instruments used to record the motion of the ground during an earthquake. They are installed in the ground throughout the world and operated as part of a seismographic network. The earliest "seismoscope" was invented by the Chinese philosopher Chang Heng in A.D. 132.Seismogram—A real-time record of earthquake ground motion recorded by a seismograph. Seismograms are the records (paper copy or computer (See seismograph.) Surface Wave—waves that move close to or on the outside surface of the Earth rather than through the deep interior like the...A seismograph, or seismometer, is an instrument used to detect and record earthquakes. Generally, it consists of a mass attached to a fixed base. During an earthquake, the base moves and the mass does not. Seismograph—an instrument that records vibrations of the Earth, especially earthquakes.

Jump to navigation Jump to go looking Kinemetrics seismograph. Part of a sequence onEarthquakes Types Foreshock Aftershock Blind thrust Doublet Interplate Intraplate Megathrust Remotely brought on Slow Submarine Supershear Tsunami Earthquake swarm Causes Fault movement Volcanism Induced seismicity Characteristics Epicenter Hypocenter Shadow zone Seismic waves P wave S wave Measurement Seismometer Seismic magnitude scales Seismic depth scales Prediction Coordinating Committee forEarthquake Prediction Forecasting Other topics Shear wave splitting Adams–Williamson equation Flinn–Engdahl regions Earthquake engineering Seismite Seismology Earth Sciences PortalCategory Related topicsvte

A seismometer is an instrument that responds to floor motions, reminiscent of caused by earthquakes, volcanic eruptions, and explosions. Seismometers are typically mixed with a timing instrument and a recording device to form a seismograph.[1] The output of such a tool—previously recorded on paper (see image) or movie, now recorded and processed digitally—is a seismogram. Such knowledge is used to locate and represent earthquakes, and to review the Earth's internal structure.

Basic rules

Basic horizontal-motion seismograph. The inertia of the spherical weight has a tendency to carry the pen nonetheless while the base moves backward and forward.

A easy seismometer, touchy to up-down motions of the Earth, is like a weight putting from a spring, each suspended from a frame that moves along side any movement detected. The relative movement between the weight (known as the mass) and the frame provides a measurement of the vertical floor movement. A rotating drum is connected to the frame and a pen is attached to the weight, thus recording any ground movement in a seismogram.

Any motion of the floor moves the body. The mass has a tendency not to move as a result of of its inertia, and by means of measuring the movement between the body and the mass, the movement of the floor may also be made up our minds.

Early seismometers used optical levers or mechanical linkages to magnify the small motions involved, recording on soot-covered paper or photographic paper. Modern instruments use electronics. In some methods, the mass is held just about immobile relative to the frame via an digital negative feedback loop. The motion of the mass relative to the body is measured, and the comments loop applies a magnetic or electrostatic power to stay the mass nearly immobile. The voltage had to produce this pressure is the output of the seismometer, which is recorded digitally.

In different systems the weight is allowed to transport, and its motion produces an electrical price in a coil hooked up to the mass which voltage moves via the magnetic field of a magnet connected to the body. This design is steadily used in a geophone, which is utilized in exploration for oil and gas.

Seismic observatories normally have instruments measuring three axes: north-south (y-axis), east-west (x-axis), and vertical (z-axis). If just one axis is measured, it is generally the vertical as a result of it is much less noisy and offers better data of some seismic waves.

The foundation of a seismic station is significant.[2] A certified station is every so often mounted on bedrock. The very best mountings is also in deep boreholes, which steer clear of thermal results, flooring noise and tilting from weather and tides. Other tools are frequently fastened in insulated enclosures on small buried piers of unreinforced concrete. Reinforcing rods and aggregates would distort the pier as the temperature changes. A website online is always surveyed for ground noise with a brief set up earlier than pouring the pier and laying conduit. Originally, European seismographs had been placed in a explicit house after a harmful earthquake. Today, they are spread to supply suitable protection (in the case of weak-motion seismology) or concentrated in high-risk areas (strong-motion seismology).[3]

Nomenclature

The phrase derives from the Greek σεισμός, seismós, a shaking or quake, from the verb σείω, seíō, to shake; and μέτρον, métron, to measure, and used to be coined via David Milne-Home in 1841, to explain an tool designed by Scottish physicist James David Forbes.[4]

Seismograph is another Greek time period from seismós and γράφω, gráphō, to draw. It is incessantly used to mean seismometer, despite the fact that it is extra appropriate to the older instruments wherein the measuring and recording of flooring movement had been combined, than to fashionable systems, during which these functions are separated. Both types provide a steady file of ground movement; this record distinguishes them from seismoscopes, which simply indicate that motion has came about, in all probability with some simple measure of how large it was once.[5]

The technical self-discipline relating to such devices is called seismometry,[6] a branch of seismology.

The idea of measuring the "shaking" of one thing signifies that the word "seismograph" may well be used in a more total sense. For instance, a tracking station that tracks modifications in electromagnetic noise affecting amateur radio waves gifts an rf seismograph.[7] And Helioseismology studies the "quakes" on the Sun.[8]

History

The first seismometer used to be made in China all through the 2nd century.[9] The first Western description of the instrument comes from the French physicist and priest Jean de Hautefeuille in 1703.[10] The trendy seismometer used to be evolved in the 19th century.[3]

In December 2018, a seismometer used to be deployed on the planet Mars by the InSight lander, the first time a seismometer was once placed onto the floor of another planet.[11]

Ancient technology Replica of Zhang Heng's seismoscope Houfeng Didong Yi See additionally: List of Chinese inventions

In AD 132, Zhang Heng of China's Han dynasty invented the first seismoscope (by way of the definition above), which used to be referred to as Houfeng Didong Yi (translated as, "instrument for measuring the seasonal winds and the movements of the Earth"). The description now we have, from the History of the Later Han Dynasty, says that it was a huge bronze vessel, about 2 meters in diameter; at 8 points around the top had been dragon's heads conserving bronze balls. When there was once an earthquake, one of the dragons' mouths would open and drop its ball into a bronze toad at the base, making a sound and supposedly appearing the route of the earthquake. On no less than one instance, almost certainly at the time of a massive earthquake in Gansu in AD 143, the seismoscope indicated an earthquake even supposing one used to be not felt. The available text says that inside of the vessel was a central column that might move alongside 8 tracks; that is concept to consult with a pendulum, despite the fact that it's not identified exactly how this was once related to a mechanism that might open only one dragon's mouth. The first earthquake recorded through this seismoscope was once supposedly "somewhere in the east". Days later, a rider from the east reported this earthquake.[9][12]

Modern designs Milne horizontal pendulum seismometer. One of the Important Cultural Properties of Japan. Exhibit in the National Museum of Nature and Science, Tokyo, Japan.

By the thirteenth century, seismographic gadgets existed in the Maragheh observatory in Persia. French physicist and priest Jean de Hautefeuille built one in 1703.[10] After 1880, most seismometers were descended from those evolved by means of the workforce of John Milne, James Alfred Ewing and Thomas Gray, who labored as foreign-government advisors in Japan from 1880 to 1895.[3] These seismometers used damped horizontal pendulums. After World War II, these were tailored into the widely used Press-Ewing seismometer.

An early special-purpose seismometer consisted of a huge, stationary pendulum, with a stylus on the bottom. As the earth started to move, the heavy mass of the pendulum had the inertia to stay nonetheless within the body. The result is that the stylus scratched a development corresponding with the Earth's movement. This sort of strong-motion seismometer recorded upon a smoked glass (glass with carbon soot). While no longer sensitive enough to discover distant earthquakes, this device may just indicate the route of the force waves and thus help in finding the epicenter of a local quake. Such instruments were useful in the analysis of the 1906 San Francisco earthquake. Further analysis was once carried out in the 1980s, using these early recordings, enabling a extra actual choice of the preliminary fault spoil location in Marin county and its subsequent progression, mostly to the south.

Later, professional suites of tools for the worldwide usual seismographic network had one set of instruments tuned to oscillate at fifteen seconds, and the different at 90 seconds, each and every set measuring in 3 instructions. Amateurs or observatories with limited method tuned their smaller, less sensitive tools to 10 seconds. The fundamental damped horizontal pendulum seismometer swings like the gate of a fence. A heavy weight is fixed on the point of a lengthy (from 10 cm to a number of meters) triangle, hinged at its vertical edge. As the floor moves, the weight remains unmoving, swinging the "gate" on the hinge.

The merit of a horizontal pendulum is that it achieves very low frequencies of oscillation in a compact tool. The "gate" is quite tilted, so the weight tends to slowly return to a central place. The pendulum is adjusted (sooner than the damping is put in) to oscillate as soon as in line with 3 seconds, or as soon as according to thirty seconds. The general-purpose instruments of small stations or amateurs most often oscillate once consistent with ten seconds. A pan of oil is placed underneath the arm, and a small sheet of metal mounted on the underside of the arm drags in the oil to damp oscillations. The stage of oil, place on the arm, and angle and size of sheet is adjusted until the damping is "critical", that is, almost having oscillation. The hinge may be very low friction, often torsion wires, so the only friction is the inner friction of the wire. Small seismographs with low proof plenty are positioned in a vacuum to reduce disturbances from air currents.

Zollner described torsionally suspended horizontal pendulums as early as 1869, however developed them for gravimetry reasonably than seismometry.

Early seismometers had an association of levers on jeweled bearings, to scratch smoked glass or paper. Later, mirrors mirrored a mild beam to a direct-recording plate or roll of photographic paper. Briefly, some designs returned to mechanical movements to save money. In mid-twentieth-century systems, the mild used to be mirrored to a pair of differential digital photosensors referred to as a photomultiplier. The voltage generated in the photomultiplier was used to power galvanometers which had a small mirror mounted on the axis. The shifting mirrored mild beam would strike the floor of the turning drum, which was once lined with photo-sensitive paper. The expense of creating picture touchy paper brought about many seismic observatories to switch to ink or thermal-sensitive paper.

Modern tools

Simplified LaCoste suspension the usage of a zero-length spring CMG-40T triaxial broadband seismometer Seismometer without housing; introduced all through a demonstration for youngsters about earthquakes at Alfred Wegener Institute.

Modern tools use digital sensors, amplifiers, and recording units. Most are broadband protecting a wide range of frequencies. Some seismometers can measure motions with frequencies from 500 Hz to 0.00118 Hz (1/500 = 0.002 seconds in line with cycle, to at least one/0.00118 = 850 seconds according to cycle). The mechanical suspension for horizontal instruments stays the garden-gate described above. Vertical instruments use some sort of constant-force suspension, reminiscent of the LaCoste suspension. The LaCoste suspension uses a zero-length spring to supply a long period (high sensitivity).[13][14] Some trendy instruments use a "triaxial" design, during which 3 similar movement sensors are set at the similar attitude to the vertical but a hundred and twenty degrees aside on the horizontal. Vertical and horizontal motions can be computed from the outputs of the 3 sensors.

Seismometers unavoidably introduce some distortion into the signals they measure, however professionally designed systems have moderately characterized frequency transforms.

Modern sensitivities are available in 3 wide ranges: geophones, 50 to 750 V/m; native geologic seismographs, about 1,500 V/m; and teleseismographs, used for global survey, about 20,000 V/m. Instruments are available 3 main varieties: brief length, lengthy length and broadband. The brief and long duration measure pace and are very sensitive, then again they 'clip' the sign or pass off-scale for ground motion this is stable sufficient to be felt by way of other people. A 24-bit analog-to-digital conversion channel is common. Practical units are linear to more or less one part in line with million.

Delivered seismometers include two types of output: analog and electronic. Analog seismographs require analog recording equipment, perhaps including an analog-to-digital converter. The output of a electronic seismograph may also be simply input to a pc. It gifts the knowledge in a standard electronic layout (often "SE2" over Ethernet).

Teleseismometers A low-frequency 3-direction ocean-bottom seismometer (quilt removed). Two lots for x- and y-direction may also be noticed, the third one for z-direction is below. This type is a CMG-40TOBS, manufactured by Güralp Systems Ltd and is a part of the Monterey Accelerated Research System.

The trendy broadband seismograph can record a very wide fluctuate of frequencies. It is composed of a small "proof mass", confined via electric forces, driven by way of sophisticated electronics. As the earth moves, the electronics attempt to dangle the mass steady via a comments circuit. The amount of drive necessary to reach this is then recorded.

In maximum designs the electronics holds a mass immobile relative to the frame. This tool is called a "force balance accelerometer". It measures acceleration as an alternative of velocity of ground motion. Basically, the distance between the mass and a few part of the frame is measured very precisely, via a linear variable differential transformer. Some tools use a linear variable differential capacitor.

That size is then amplified through digital amplifiers hooked up to parts of an digital damaging comments loop. One of the amplified currents from the unfavourable feedback loop drives a coil very like a loudspeaker. The result is that the mass stays just about motionless.

Most instruments measure without delay the floor motion the use of the distance sensor. The voltage generated in a sense coil on the mass by way of the magnet immediately measures the immediate speed of the floor. The current to the power coil provides a touchy, accurate size of the force between the mass and frame, thus measuring at once the ground's acceleration (the use of f=ma the place f=pressure, m=mass, a=acceleration).

One of the proceeding problems with sensitive vertical seismographs is the buoyancy of their masses. The uneven adjustments in drive brought about via wind blowing on an open window can simply exchange the density of the air in a room sufficient to motive a vertical seismograph to show spurious indicators. Therefore, most professional seismographs are sealed in inflexible gas-tight enclosures. For example, this is why a commonplace Streckeisen style has a thick glass base that should be glued to its pier with out bubbles in the glue.

It may seem logical to make the heavy magnet serve as a mass, however that topics the seismograph to mistakes when the Earth's magnetic field moves. This could also be why seismograph's shifting portions are made from a material that interacts minimally with magnetic fields. A seismograph could also be sensitive to modifications in temperature such a lot of tools are made out of low growth fabrics comparable to nonmagnetic invar.

The hinges on a seismograph are usually patented, and by way of the time the patent has expired, the design has been advanced. The maximum a hit public domain designs use skinny foil hinges in a clamp.

Another factor is that the transfer function of a seismograph will have to be as it should be characterized, so that its frequency response is understood. This is frequently the a very powerful distinction between professional and novice tools. Most tools are characterized on a variable frequency shaking table.

Strong-motion seismometers

Another sort of seismometer is a digital strong-motion seismometer, or accelerograph. The knowledge from such an tool is very important to know the way an earthquake impacts man-made constructions, thru earthquake engineering. The recordings of such tools are the most important for the review of seismic danger, thru engineering seismology.

A powerful-motion seismometer measures acceleration. This can be mathematically built-in later to offer pace and position. Strong-motion seismometers don't seem to be as sensitive to floor motions as teleseismic instruments but they keep on scale all over the strongest seismic shaking.

Strong motion sensors are used for intensity meter applications.

Other bureaucracy A Kinemetrics seismograph, formerly utilized by the United States Department of the Interior.

Accelerographs and geophones are frequently heavy cylindrical magnets with a spring-mounted coil within. As the case moves, the coil tends to stick stationary, so the magnetic box cuts the wires, inducing present in the output wires. They receive frequencies from several hundred hertz down to 1 Hz. Some have electronic damping, a low-budget technique to get some of the efficiency of the closed-loop wide-band geologic seismographs.

Strain-beam accelerometers constructed as integrated circuits are too insensitive for geologic seismographs (2002), but are widely utilized in geophones.

Some other touchy designs measure the present generated via the go with the flow of a non-corrosive ionic fluid thru an electret sponge or a conductive fluid through a magnetic field.

Interconnected seismometers

Seismometers spaced in a seismic array may also be used to exactly locate, in three dimensions, the supply of an earthquake, the usage of the time it takes for seismic waves to propagate away from the hypocenter, the beginning level of fault rupture (See also Earthquake location). Interconnected seismometers are extensively utilized, as section of the International Monitoring System to hit upon underground nuclear take a look at explosions, in addition to for Earthquake early warning systems. These seismometers are incessantly used as phase of a huge scale governmental or clinical mission, but some organizations equivalent to the Quake-Catcher Network, can use residential length detectors constructed into computers to locate earthquakes as well.

In mirrored image seismology, an array of seismometers symbol sub-surface features. The information are diminished to photographs the use of algorithms very similar to tomography. The data aid strategies resemble the ones of computer-aided tomographic scientific imaging X-ray machines (CAT-scans), or imaging sonars.

A world array of seismometers can in reality image the inner of the Earth in wave-speed and transmissivity. This type of system makes use of events such as earthquakes, impact occasions or nuclear explosions as wave assets. The first efforts at this method used handbook knowledge aid from paper seismograph charts. Modern digital seismograph information are higher tailored to direct computer use. With reasonably priced seismometer designs and web get admission to, amateurs and small establishments have even formed a "public seismograph network".[15]

Seismographic systems used for petroleum or different mineral exploration traditionally used an explosive and a wireline of geophones unrolled in the back of a truck. Now most short-range systems use "thumpers" that hit the ground, and a few small commercial methods have such just right digital sign processing that a few sledgehammer strikes provide sufficient sign for short-distance refractive surveys. Exotic go or two-dimensional arrays of geophones are every so often used to accomplish 3-dimensional reflective imaging of subsurface features. Basic linear refractive geomapping software (once a black art) is to be had off-the-shelf, operating on laptop computer systems, the use of strings as small as three geophones. Some systems now come in an 18" (0.5 m) plastic field case with a computer, show and printer in the cover.

Small seismic imaging systems are actually sufficiently inexpensive for use via civil engineers to survey basis websites, locate bedrock, and in finding subsurface water.

Fiber optic cables as seismometers

A brand new method for detecting earthquakes has been discovered, using fiber optic cables.[16] In 2016 a crew of metrologists working frequency metrology experiments in England seen noise with a wave-form resembling the seismic waves generated by way of earthquakes. This used to be found to check seismological observations of an Mw6.0 earthquake in Italy, ~1400 km away. Further experiments in England, Italy, and with a submarine fiber optic cable to Malta detected additional earthquakes, together with one 4,100 km away, and an ML3.Four earthquake 89 km away from the cable.

Seismic waves are detectable as a result of they reason micrometer-scale adjustments in the size of the cable. As the length modifications so does the time it takes a packet of mild to traverse to the far finish of the cable and back (the use of a moment fiber). Using ultra-stable metrology-grade lasers, those extremely minute shifts of timing (on the order of femtoseconds) appear as phase-changes.

The level of the cable first disturbed by means of an earthquake's p-wave (necessarily a sound wave in rock) can be made up our minds through sending packets in both directions in the looped pair of optical fibers; the difference in the arrival instances of the first pair of perturbed packets indicates the distance along the cable. This point is also the point closest to the earthquake's epicenter, which must be on a aircraft perpendicular to the cable. The distinction between the p-wave/s-wave arrival occasions provides a distance (below very best stipulations), constraining the epicenter to a circle. A moment detection on a non-parallel cable is needed to resolve the ambiguity of the resulting resolution. Additional observations constrain the location of the earthquake's epicenter, and might unravel the depth.

This method is predicted to be a boon in looking at earthquakes, particularly the smaller ones, in vast parts of the world ocean the place there aren't any seismometers, and at a cost much less expensive than ocean bottom seismometers.

Recording

Viewing of a Develocorder movie Matsushiro Seismological Observatory Further knowledge: Seismogram

Today, the most commonplace recorder is a computer with an analog-to-digital converter, a disk force and an internet connection; for amateurs, a PC with a sound card and related tool is ok. Most techniques record regularly, however some record only when a sign is detected, as proven by a temporary building up in the variation of the sign, compared to its long-term moderate (which will vary slowly as a result of of modifications in seismic noise), also known as a STA/LTA cause.

Prior to the availability of digital processing of seismic data in the late Seventies, the records have been executed in a few different forms on differing types of media. A "Helicorder" drum was a tool used to file knowledge into photographic paper or in the sort of paper and ink. A "Develocorder" was once a system that file knowledge from up to 20 channels into a 16-mm film. The recorded film may also be seen by way of a system. The studying and measuring from those sorts of media can also be done by means of hand. After the electronic processing has been used, the archives of the seismic information have been recorded in magnetic tapes. Due to the deterioration of older magnetic tape medias, huge number of waveforms from the archives aren't recoverable.[17][18]

See additionally

Accelerometer Galitzine, Boris Borisovich Geophone IRIS Consortium Lehmann, Inge Milne, John Oldham, Richard Dixon Pacific Northwest Seismic Network Plate tectonics Quake-Catcher Network Richter magnitude scale Seismogram

References

^ .mw-parser-output cite.citationfont-style:inherit.mw-parser-output .citation qquotes:"\"""\"""'""'".mw-parser-output .id-lock-free a,.mw-parser-output .citation .cs1-lock-free abackground:linear-gradient(transparent,clear),url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")correct 0.1em middle/9px no-repeat.mw-parser-output .id-lock-limited a,.mw-parser-output .id-lock-registration a,.mw-parser-output .quotation .cs1-lock-limited a,.mw-parser-output .citation .cs1-lock-registration abackground:linear-gradient(transparent,transparent),url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")appropriate 0.1em middle/9px no-repeat.mw-parser-output .id-lock-subscription a,.mw-parser-output .quotation .cs1-lock-subscription abackground:linear-gradient(clear,transparent),url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")appropriate 0.1em center/9px no-repeat.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registrationcolor:#555.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration spanborder-bottom:1px dotted;cursor:lend a hand.mw-parser-output .cs1-ws-icon abackground:linear-gradient(clear,transparent),url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em middle/12px no-repeat.mw-parser-output code.cs1-codecolor:inherit;background:inherit;border:none;padding:inherit.mw-parser-output .cs1-hidden-errorshow:none;font-size:100%.mw-parser-output .cs1-visible-errorfont-size:100%.mw-parser-output .cs1-maintshow:none;colour:#33aa33;margin-left:0.3em.mw-parser-output .cs1-formatfont-size:95%.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-leftpadding-left:0.2em.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-rightpadding-right:0.2em.mw-parser-output .quotation .mw-selflinkfont-weight:inheritAgnew, Duncan Carr (2003), "Ch. 1: History of Seismology", International Handbook of Earthquake & Engineering Seismology, Part A, pp. 3–11, ISBN 978-0-12-440652-0, LCCN 2002103787, p. 269. See also the USGS Seismometers, seismographs, seismograms webpage. ^ Erhard Wielandt's 'Seismic Sensors and their Calibration' Archived 2010-09-24 at the Wayback Machine- Current (2002) reference by way of a widely consulted skilled. ^ a b c Reitherman, Robert (2012). Earthquakes and Engineers: an International History. Reston, VA: ASCE Press. pp. 122–125. ISBN 9780784410714. Archived from the original on 2012-07-26. ^ Ben-Menahem, A. (2009). Historical Encyclopedia of Natural and Mathematical Sciences , Volume 1. Springer. p. 2657. ISBN 9783540688310. Retrieved 28 August 2012. ^ Richter, C.F. (1958). Elementary Seismology. San Francisco: W.H. Freeman. ^ William H.K. Lee; Paul Jennings; Carl Kisslinger; Hiroo Kanamori (27 September 2002). International Handbook of Earthquake & Engineering Seismology. Academic Press. pp. 283–. ISBN 978-0-08-048922-3. Retrieved 29 April 2013. ^ "The RF Seismograph". www.nsarc.ca. Retrieved 28 March 2018. ^ "The Singing Sun". solar-center.stanford.edu. Retrieved 28 March 2018. ^ a b Sleeswyk AW, Sivin N (1983). "Dragons and toads: the Chinese seismoscope of BC. 132". Chinese Science. 6: 1–19. ^ a b Joseph Needham (1985). Science and Civilisation in China: Paper and Printing. Cambridge University Press. p. 122. ISBN 978-0-521-08690-5. Retrieved 16 April 2013. In the Southern Sung dynasty, reward money for bestowing upon officers via the imperial court docket was wrapped in paper envelopes (chih pao) ^ Cook, Jia-Rui; Good, Andrew (19 December 2018). "NASA's InSight Places First Instrument on Mars". NASA. Retrieved 20 December 2018. ^ Needham, Joseph (1959). Science and Civilization in China, Volume 3: Mathematics and the Sciences of the Heavens and the Earth. Cambridge: Cambridge University Press. pp. 626–635. ^ "Physics of the Zero-Length Spring of Geoscience". physics.mercer.edu. Retrieved 28 March 2018. ^ A Biography of Lucien LaCoste, inventor of the zero-length spring Archived 2007-03-20 at the Wayback Machine ^ "Redwood City Public Seismic Network". psn.quake.web. Retrieved 28 March 2018. ^ Marra, Giuseppe; Clivati, Cecilia; Luckett, Richard; Tampellini, Anna; Kronjäger, Jochen; Wright, Louise; Mura, Alberto; Levi, Filippo; Robinson, Stephen; Xuereb, André; Baptie, Brian; Calonico, Davide (3 August 2016), "Ultrastable laser interferometry for earthquake detection with terrestrial and submarine cables", Science, 361 (6401): 486–490, doi:10.1126/science.aat4458, PMID 29903881. ^ Hutton, Kate; Yu, Ellen. "NEWS FLASH!! SCSN Earthquake Catalog Completed!!" (PDF). Seismological Laboratory, Caltech. Archived from the unique (PDF) on 14 July 2014. Retrieved 4 July 2014. ^ Fogleman, Kent A.; Lahr, John C.; Stephens, Christopher D.; Page, Robert A. (June 1993). Earthquake Locations Determined by way of the Southern Alaska Seismograph Network for October 1971 thru May 1989 (Report). USGS.

External hyperlinks

Wikimedia Commons has media related to Seismometers.The history of early seismometers The Lehman beginner seismograph, from Scientific American- now not designed for calibrated size. Sean Morrisey's professional design of an newbie teleseismograph Also see Keith Payea's version Both accessed 2010-9-29 Morrissey was once a professional seismographic software engineer. This awesome design uses a zero-length spring to succeed in a 60-second length, energetic comments and a uniquely convenient variable reluctance differential transducer, with parts scavenged from a hardware store. The frequency become is thoroughly designed, unlike maximum novice instruments. Morrisey is deceased, however the website online remains up as a public carrier. SeisMac is a loose software for recent Macintosh computer computers that implements a real-time three-axis seismograph. The Development Of Very-Broad-Band Seismography: Quanterra And The Iris Collaboration discusses the history of building of the primary era in international earthquake research. Video of seismograph at Hawaiian Volcano Observatory – on Flickr – retrieved on 2009-06-15. Seismoscope – Research References 2012 Iris EDU – How Does A Seismometer Work?

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