What is a Seismograph?
A seismograph is simply a device that can measure the intensity of a “seismic” type of activity such as an earthquake. But aside from the earthquake’s intensity, seismographs can also measure and record the earthquake’s duration and direction. But unknown to many people, seismographs may also be used to record information from other activities such as tidal waves, big explosions, and other occurrences that result in the shaking of the ground.

Many people interchange the word “seismometer” for the “seismograph”. But generally, seismographs refer to older devices and scientific instruments that record and measure seismic activity using a single system. Seismometers meanwhile are used for modern devices which have separate systems and mechanisms for recording and measuring a particular seismic activity.

The basic concept of seismographs or seismometers is that it involves an internal mass or weight since it will also move during an earthquake. Using a system of levers, weights, springs, and electronics in modern versions, seismographs are able to record information on the shaking of the ground. The earliest version of this device was said to originate in China through a device called a “seismoscope”, which basically indicates whether some form of ground motion occurred and perhaps very little information on its intensity. Over the years, this simple device has evolved and has been improved to provide more reliable data on the earth’s seismic activities. Modern devices today employ electronics and are able to detect the earth’s motion using different frequencies. Some seismographs or seismometers today even have the capability of locating the source of an earthquake with great precision technology.

Information taken from seismographs and similar devices has proven very essential to human lives. Though much of the earth’s natural seismic activities cannot be precisely predicted, studies of these events are still a great help in determining its impact to the people. But aside from its use on monitoring seismic activities, seismographs are also used by some government organizations and intelligence agencies to test explosives and artillery.