www.Primo.com: About seismometer.

Seismometers (Greek : seismos : earthquakes and metero : measure ) is a tool or a vibration sensor , which is usually used to detect earthquakes or vibrations on the surface of the soil . Recording the results of this tool is called seismogram .

Prototypes of the device was first introduced in the year 132 BC by the mathematician of the Han Dynasty named Chang Heng . With this tool people at that time could determine from which direction the earthquake.
With the development of technology nowadays seismometer capability can be improved , so that it can record vibrations within a fairly wide range of frequencies . A tool like this is called broadband seismometers .
Seismograph is a device that measures and records earthquake . In principle , the seismograph consists of a weight hanger and a pointed tip like a pencil. That way, it can be seen the strength and direction of the motion picture through the earth quake recorded in the form of seismograms .

The working principle .

Seismograph has sensitive instruments that can detect seismic waves generated by earthquakes . Seismic waves that occurred during the earthquake depicted as wavy lines on the seismograms . Seismologist measuring these lines and calculate the magnitude of the earthquake.
Previously , only seismograph can detect horizontal movement , but this time the seismograph has been able to record movements vertically and laterally . Seismograph using two mechanical motion and electromagnetic seismographer . Both types of mechanical movement can detect both vertical movement and horizontal movement of the pendular used depending on whether vertical or horizontal .
Modern uses electromagnetic seismograph seismographer to move volatility pull wire system to a magnetic field . The events that cause vibration is then detected through spejlgalvanometer . seismograph

History .

In the mid 18th century , an earthquake is measured with an instrument called seismokop . Seismokop seismic recording equipment is the most primitive . Seismokop consists of a simple container filled with water or mercury . When an earthquake happens , the fluid will move up and down due to the earthquake that occurred vibration .
The big breakthrough for measuring earthquakes came in 1920 , when two American scientists developed a tool called the Wood - Anderson seismograph . This tool is more sensitive than the existing seismograph at that time , so immediately widely used around the world and became the forerunner of a seismograph that now exist and thrive . Currently , many seismographs used by Seismologist in studying fault and earthquake .

Earthquake Measuring Classification .

Seismograph using two different classifications for measuring the seismic waves produced by earthquakes , the earthquake magnitude and intensity of earthquakes . The second classification of these measurements using different measurement scales . The scale consists of measuring earthquake on the Richter Scale and Mercalli Scale . Richter scale is used to describe the magnitude of the earthquake while the Mercalli Scale is used to indicate the intensity of an earthquake , or the effect of the earthquake on land , buildings , and human .

Earthquake Magnitude classification .

In 1935 , an American Geophysics named Charles Francis Richter ( 1900-1985 ) along with other Geophysics named Beno Gutenberg ( 1889-1960 ) developed a scale which in principle can compare seismograms to get an overview of all the tremors of similar strength . The scale called the Richter Scale and until now recognized as a common standard magnitude scale .
Designed with the logarithmic Richter scale , which means that each step shows the power that is 10 times more powerful than its predecessor . 5 on the Richter Scale indicates the crunch, which is 10 times stronger than one in 4 and 100 times stronger than one in 3 on the Richter Scale . This calculation is often referred to as the open Richter scale , because it does not operate with no upper limit . Richter Scale size can be seen in the following table :

Richter Scale Size Specification

1.0 to 3.0 is labeled by humans .
3.0 to 3.9 was felt by people around the epicenter.
Chandelier started to shake .
4.0 to 4.9 Feel the vibration once . Window vibrating , rippling water surface , leaves the door open and
closed itself .
5.0 to 5.9 is very difficult to stand up straight . Porcelain and
glass tableware , weak walls collapsed , and water
surface water waves formed on the mainland .
6.0 to 6.9 Stone collapsed together, the collapse of high-rise
buildings, buildings fall of the weak, cracked-right
in the ground.
7.0 to 7.9 Landslides , collapsing bridges , dams damaged and destroyed . Some buildings remain , large cracks in
the ground , damaged railroad tracks . Total damage occurred in the area of the earthquake .
8.0 - ... Can cause serious damage in areas within a radius
of several hundred kilometers from the earthquake
region .

Classification of Earthquake Intensity .

In 1902 , an Italian volcano named Giuseppe Mercalli ( 1850-1914 ) classifying the intensity scale earthquakes and their effects on humans , building ( buildings ) , and natural ( soil ) . The classification is called the Mercalli scale is determined based on the damage caused by the earthquake and interviews to the victims , so it is very subjective . Therefore , in 1931 an American scientist of modifying the Mercalli Scale and until now used in many areas of the earthquake . Classification Mercalli Scale of earthquake intensity can be seen in the following table :

Size Specification

I Recorded only by seismographs .
II Vibration is felt only by people around the epicenter.
III Vibration is felt by some people .
IV vibrations will be felt by many people . Porcelain and glassware
jingle sides and doors rattling .
V Animals feel difficulty and fear . The building began to sway . Many people will wake up from sleep .
VI Objects began to fall from shelves .
Many people are anxious VII , cracks in walls and roads .
VIII shift home goods .
IX widespread panic , landslides , many roofs and walls collapsed .
X Many buildings were damaged , wide cracks in the ground
reaching up to 1 meter .
XI Cracks in the ground widening , numerous landslides and rock
falls .
XII Most of the buildings were destroyed , the soil surface becomes a
radical change.

There are several types of fault , including :

Normal Fault.
Up Fault (thrust fault ).
Fault shear ( strike - slip or transform , or wrench fault ).
Fault containment.
Thank you for reading this article. Written and posted by Bambang Sunarno. sunarnobambang86@gmail.com
author:
http://schema.org/Personal.
https://plus.google.com/105319704331231770941.
name: Bambang Sunarno.
http://primadonablog.blogspot.com/2014/02/about-seismometer.html
DatePublished: February 17, 2014 at 14:59

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