Equipment to measure earthquakes is called Seismograph / seismometer
To measure the vibrations at the surface of the soil. The recordings of these tools is called seismogram.
Modern tool uses electronic sensors, amplifiers and recording equipment. Most broadband covers a wide range of frequencies.
Seismometer is an instrument that measures ground motion, including seismic waves generated by earthquakes, volcanic eruptions, earthquakes and other sources. Records of seismic waves allow seismologists to map the interior of the Earth and locate and measure the size of different sources, www.whatcausesearthquakes.com
And the difference seismometer seismograph
Seismograph is a device that measures and records the earthquake. In principle, the seismograph consists of a ring sinker and a pointed tip like a pencil. By doing so, it can be seen the strength and direction of the earthquake through the Earth’s motion picture recorded in the form of seismograms.
In short: seismometers and seismographs are identical, they are instruments to record the motion of the Earth associated with earthquakes, volcanic eruptions, earthquakes or other sources such as explosions. seismograph is a device detection and recording in a single instrument.
Prototypes of these tools has been first introduced in 132 BC by the mathematician of the Han Dynasty named Chang Heng. With this tool, people at that time can determine the direction from which earthquakes occur.
There are several scales used to measure the strength of earthquakes. Namely Omori scale, Mercalli, Cancani, and Richter.
Richter scale is the scale of the most famous and most frequently used to measure the strength of the quake, generally referred to by the magnitude (M).
Based on the scales, we can understand the potential power of an earthquake, which in turn is useful in urban planning. Such as highway design, construction, flyovers, airports, and others.
Based on the Richter scale, an earthquake can be divided into:
- > 3.5 Recorded, but usually is not.
- 3.5 to 5.4 Often felt, but rarely causes damage.
- <6.0 Potentially causing serious damage to the building that is less strong.
- Potentially 6.1-6.9 cause physical damage and casualties to a radius of 100 km.
- 7.0-7.9 Classified as a large earthquake. Potentially causing serious damage to wide area coverage.
- > 8 massive earthquake. Potentially causing serious damage, with a coverage area of several hundred kilometers.
With more advanced and development of technology, now earthquake detection tool can already be equipped with record yields more accurate and detailed.