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Topic: Seismometer


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  MARS - Seafloor Seismometer
The seismometer measures this relative motion to produce a graph of the shaking.
As with most seafloor instruments, seismometers have to run on batteries and their data are not accessible for several months while the instrument sits on the bottom.
1997 news release on the seafloor seismometer's precursor.
www.mbari.org /mars/general/seismometer.html   (748 words)

  
 First-Year Curricula: Arizona State University Projects / Building a Seismometer
The seismometer, in essence, employs mechanical oscillatory motion (a pendulum) to measure other wave phenomena (seismic waves traveling through the earth) and electromagnetics to convert the mechanical motion to electrical energy which can be amplified and examined on the classroom PCs.
A seismometer should be able to detect minute ripples in the earth produced by someone walking across a room as well as the substantial motion of the earth's crust caused by earthquakes.
It is true that the world's best seismometers have massive frames anchored to piers sunk in bedrock and moving arms pivoting on sapphire bushings and sophisticated motors turning precision drums of paper for recording the pen movements.
www.foundationcoalition.org /resources/first-year/asu/course-materials/projects/seismometer.html   (0 words)

  
  ScienceDaily: Seismometer   (Site not responding. Last check: )
Seismometer are used by seismologists to measure and record seismic waves.
Moment magnitude scale -- The moment magnitude scale was introduced in 1979 by Tom Hanks and Hiroo Kanamori as a successor to the Richter scale and is used by seismologists to compare the energy released by...
Seismometer -- Seismometer are used by seismologists to measure and record seismic waves.
www.sciencedaily.com /encyclopedia/Seismometer   (1415 words)

  
 Seismometer Summary
Seismometer (in Greek seismos = earthquake and metero = measure) are used by seismologists to measure and record seismic waves.
The modern broad-band seismometer (so called because of the capacity to record a very broad range of frequencies) consists of a small 'proof mass', confined by electrical forces, driven by sophisticated electronics.
Seismometers spaced in an array can also be used to precisely locate, in three dimensions, the source of an earthquake, using the time it takes for seismic waves to propagate away from the hypocenter, the initiating point of fault rupture (See also Earthquake location).
www.bookrags.com /Seismometer   (0 words)

  
  Seismometer off Muroto Cape
Each seabed seismometer is loaded with an acceleration detector of three orthogonal constituents X, Y and Z. Each acceleration detector converts servo circuit current output into direct current voltage and outputs it.
Regarding the ocean bottom seismometers, for construction reasons, the direction of the cables is not in a north-south direction, because several devices are installed in a series.
The seismometer is cylindrical, and its polarity is as shown in Fig.
www.jamstec.go.jp /scdc/html_sysindex_e/obsmuroto.html   (412 words)

  
 Foundation Coalition: Active/Cooperative Learning
The seismometer, in essence, employs mechanical oscillatory motion (a pendulum) to measure other wave phenomena (seismic waves traveling through the earth) and electromagnetics to convert the mechanical motion to electrical energy that can be amplified and examined on the classroom PCs.
A seismometer should be able to detect minute ripples in the earth produced by someone walking across a room as well as the substantial motion of the earth's crust caused by earthquakes.
It is true that the world's best seismometers have massive frames anchored to piers sunk in bedrock and moving arms pivoting on sapphire bushings and sophisticated motors turning precision drums of paper for recording the pen movements.
clte.asu.edu /active/lesscontseismoinstruction.htm   (646 words)

  
 Wood-Anderson Torsion Seismometer   (Site not responding. Last check: )
The Wood-Anderson seismometer was designed to be as sensitive and as nearly frictionless as possible.
This was an improvement over previous, mechanically-damped instruments, because the strength of magnetic damping is proportional to the amount of motion in the object being damped -- hence, when the instrument is at rest, the dampers provide no initial resistance to motion of the inertial mass.
Seismograms made using the Wood-Anderson seismometer were "drawn" not with a stylus or needle, but with a beam of light reflected onto photosensitive paper (not shown) from off of a mirror (m) on the inertial mass.
www.data.scec.org /Module/s3inset3.html   (164 words)

  
 Seismometer - Preamplifier Description
One of the major shortcomings of a home-made seismometer is the minuscule size of the seismic signal available at the output of the magnetic pickup coil.
Seismic disturbances cause the seismometer's frame and base to move with respect to the pendulum and magnet (and, hence, with respect to the pickup coil which is attached to the frame).
Unless the seismometer is located within 1-meter of a power transformer or electric motor, it is usually not necessary to provide for magnetic shielding of the pickup coil.
users.viawest.net /~aloomis/seisprea.htm   (892 words)

  
 SG Sensor Article
When an amateur builds a seismometer, he is most likely to choose an instrument of the electromagnetic type developed in 1906 by Boris Borisovich Golitsyn, a physicist who was also a prince of the Russian Empire.
A seismometer of this type picks up earthquake waves with a pendulum that supports a coil of insulated wire between the poles of a magnet rigidly linked to the earth.
After six months of experimenting at home we succeeded in devising a seismometer that not only behaves as though the resonant period of the pendulum exceeds 60 seconds but also dispenses with the coil and magnet and replaces vacuum tubes with solid-state circuits [see illustration on opposite page].
psn.quake.net /sgsenstxt.html   (2973 words)

  
 Deep Ocean Exploration Institute - Funded Research   (Site not responding. Last check: )
Modern ocean bottom seismometers are based on their terrestrial counterparts that have evolved from large instruments with drums of paper that record the movement of a needle in response to the shaking of the earth called helicorders, to small, stand-alone network appliances, which are now deployed by the thousands in the United States alone.
The seismometers allow scientists to find the source of an earthquake and determine its magnitude as soon as the energy is recorded and sent across the Internet.
The complete seismometer system includes two glass balls full of electronics and batteries, and several more that are simply full of air to float it back to the surface once a weight is released.
www.whoi.edu /institutes/doei/research/research_01freitag.htm   (812 words)

  
 Teachers' Domain: Making a Seismometer
For example, they record both the intensity of the vibration, as measured by the height of the line on the seismogram, and the vibration's frequency, which is measured by the distance between the peaks or valleys on the graph.
The seismometer the ZOOM cast members made measures earthquake (seismic) waves that move sideways, or parallel to the Earth's surface.
When the cast members bounced the table up and down by hitting it, the seismometer just bounced up and down and didn't make the big curves it made when they moved the box back and forth.
www.teachersdomain.org /resources/ess05/sci/ess/earthsys/seismometer   (581 words)

  
 ZOOM . activities . sci . Seismometer | PBS Kids
When I made my seismometer I learned that it is importaint that every thing lines up right like the marker, and the holes that you make and the biggest problem that I had was putting the holes in but other than that it worked with flying colors and it was very interseting to watch.
We made a seismometer by using a marker, clay, a cup, a 45 cm peice of string, marbles, and a topless cardboard box.
I've been studying seismometers for a science report and your design, though relatively simple, seemed liked it worked as well as some of the more high tech ones with larger masses.
pbskids.org /zoom/activities/sci/seismometer.html   (0 words)

  
 WHOI : Instruments : Ocean-Bottom Seismometer   (Site not responding. Last check: )
The seismometer's data logger and batteries have to be protected from the pressures of the deep sea.
Scientists use seismometer data to calculate the energy released by earthquakes, like the massive one in December 2004 that caused the Indian Ocean tsunami.
The seismometer itself is a small metal cylinder; the rest of the footlocker-sized OBS consists of equipment to run the seismometer (a data logger and batteries), weight to sink it to the sea floor, a remote-controlled acoustic release and flotation to bring the instrument back to the surface.
www.whoi.edu /instruments/viewInstrument.do?id=10347   (953 words)

  
 Seismometer off Kushiro-Tokach
Each seabed seismometer is loaded with an acceleration detector of three orthogonal constituents X,Y and Z, and one hydrophone sensor.
As shown in the diagram of the cable route map, the seabed seismometers are installed approx.
Regarding the seabed seismometers, for construction reasons, the direction of the cables is not in a north-south direction, because several devices are installed in a series.
www.jamstec.go.jp /scdc/html_sysindex_e/obsdetail.html   (391 words)

  
 The STM-8 Leaf Spring Seismometer   (Site not responding. Last check: )
Photo of the Seismometer Pier itself in the basement, The pier is made from concrete blocks with patio pavers on top, finished with 12"x12" glossy tiles.
A fedback seismometer can achieve a true broadband response because the parameters of the transfer function are determined primarily by four electronic components, which can be selected for the specific broadband performance desired, depending on the noise characteristics at the instrument site.
The heart of a broadband seismometer is the displacement transducer; it is the sole source of the output signal.
www.eas.slu.edu /People/STMorrissey/stmseis.html   (6837 words)

  
 [No title]
The handheld seismometer is designed to illustrate concepts of seismometry (sensing and recording the vibration or shaking of the ground generated by propagating seismic waves) and to be used as a simple seismometer for educational demonstrations and activities in seismology.
The handheld seismometer could be placed on the ground or floor to record small ground motion from nearby footsteps, or local seismic noise (such as generated by traffic) or weight drop experiments.
The Handheld Seismometer has been designed primarily for demonstration purposes and to be as simple and inexpensive as possible and to use readily-available parts.
web.ics.purdue.edu /~braile/edumod/handseis/handseis.htm   (2842 words)

  
 High Performance Wireless Research and Education Network
Modern seismometers throughout the world, including those on HPWREN, rely on electronic displacement transducers to sense motions of an inertial mass, whenever the earth's surface moves.
The fiber optic seismometer sits on the granite pier (right photo towards the bottom), which is coupled to the earth and isolated from the vault and the wood floor.
The current prototype SIFO (Seismometer Incorporating Fiber Optics) is running in an underground seismic vault at the Piñon Flats Observatory in Anza, California.
hpwren.ucsd.edu /news/20061010   (285 words)

  
 Standard Conditions
In instruments for which the recommended periods of the seismometer and galvanometer are close together, the peak of the sensitivity curve can be maintained at the proper period by altering the seismometer period in the reverse direction to the drift of the galvanometer.
The parameters which are readily adjustable in an electromagnetic seismograph are the period of the seismometer, the resistors in the coupling network, which jointly determine the overall magnification, and the damping constants of the seismometer and galvanometer.
The galvanometer period and the dynamic constants of the galvanometer and seismometer are not usually at the disposal of the operator.
www.seismo.com /msop/msop79/inst/inst5.html   (1256 words)

  
 RECENT EARTH TIDES NEAR LEONARD OKLAHOMA
The seismometer is at 840 meters depth in the borehole, which puts it about 500 feet into the Cambro-Ordivician Arbucke dolomite.
At the depth of 840 meters (2755 feet), the Guralp CMG1-TBD seismometer is at a constant internal temperature of 51.2 degrees celsius (124.2 degrees fahrenheit).
In the top of the seismometer case, a small computer, and the analog electronics in the seismometer modules, constantly use 119 milliamps of 12 VDC power.
www.okgeosurvey1.gov /tide.html   (970 words)

  
 TXAR: Seismometer Installation - 2   (Site not responding. Last check: )
During installation the seismometer will be lowered by electric winch within a foot of the bottom and then by hand for the final distance.
The seismometer is attached to the cable and ready to be lowered into the hole.
On occassion it is necessary to rotate the seismometer slightly to avoid irregularities on the floor.
www.geology.smu.edu /~hayward/Txar/seismometer.html   (316 words)

  
 BASIC Stamp Seismometer
A simple, yet capable, seismometer that teachers can use to instruct the fundamental principles of seismology can be constructed using a Basic Stamp and two Memsic 2125 accelerometers.
The seismometer can be used to do other acceleration collection tasks besides “shacking dirt.” The Stamp could be programmed to store accelerations in ROM and then dump the data to StampDAQ.
This simple, and inexpensive seismometer proves many opportunities for students to study the science of accelerations.
www.parallax.com /html_pages/resources/custapps/app_smeter.asp   (0 words)

  
 A simple Lehman type seismometer
A seismometer is a measuring device which translates slightest movements of the earth into (preferrably) an electrical signal which can be recorded and processed for example.
This knife edge is a crucial part of a seismometer since it determines the amount of force necessary to move the boom out of its rest position.
The main problem with this type of seismometer is the fact that the boom is a pendulum and will swing with its own time constant as soon as it is excited by a seismic event.
www.vaxman.de /projects/lehman_seismometer/seismometer.html   (1132 words)

  
 Modernized conventional Pendulum Seismometer
A common form of horizontal seismometer, frequently referred to as a `pendulum' is a swinging `door' or `garden-gate'.
For example, the noise floor of seismometers is commonly calculated on the basis of the equipartition theorem; i.e., a brownian noise estimate.
The problem with seismometer springs is that there is never a single pair of terms (one potential, the other kinetic) in the Hamiltonian, associated with the excitation of a Hooke's law (idealized) spring.
physics.mercer.edu /hpage/rpend.html   (2767 words)

  
 LEO seismometer reinstallation/cleaning
The casing had to be cleared of all debris before the seismometer was placed in the ground.
seismometer is leveled and positioned to line up with north.
The picture on the right shows the casing with insulation before the seismometer was reinstalled.
www.leo.lehigh.edu /projects/seismic/stationwebpage/install6.html   (122 words)

  
 Calibration of the AS-1 Seismometer
The mass consists of a magnet and other attachments on a beam that is constrained to rotate in the vertical plane about a connecting hinge on a vertical support.
Cheap Seis AD unit was used to record the signal from the seismometer.
The response anomaly is caused by the use of polarized components in circuits with both positive and negative voltages.
quake.eas.gatech.edu /MagWeb/CalReptAS-1.htm   (1965 words)

  
 Undersea seismometer captures clear signals of big quake
This instrument (known as the MOBB or Monterey Ocean Bottom Broadband seismometer) is so sensitive that it can record the vibrations created by ocean-bottom currents, ocean-surface waves, and faint echoes of earthquake waves within the ocean and seafloor.
The seismometer was buried in the seafloor to shield it from the tiny vibrations caused by ocean-bottom currents and waves at the ocean surface.
The seismometer's batteries and recording equipment were placed in a separate container about 10 meters from the seismometer, along with a current meter that helps scientists calibrate the seismometer readings to take into account any vibrations caused by bottom currents.
www.mbari.org /news/homepage/2005/mobb-sumatra.html   (0 words)

  
 TXAR: Seismometer Installation   (Site not responding. Last check: )
Installation of the seismometer begins with adjusting the free period and mass position.
The feet on the bottom of the seismometer are adjusted for a level surface.
The installation of the seismometer begins with final adjustment of the instrument for free period and a level surface.
www.geology.smu.edu /~hayward/Txar/seismometer-b.html   (252 words)

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