Since the formation of the globe, the base of the surface is constantly in motion. The earth’s crust when moving can lead to dire consequences in the form of a phenomenon such as an earthquake. When one plate crawls onto another, the internal tension of the continental crust accumulates, when passing a critical point, the accumulated energy is released, causing terrible destruction. In order to avoid casualties during the earthquake and to study the phenomenon itself, the seismograph device was invented. With its help, it became possible to determine the amount of energy released during fluctuations of the earth's crust.
What is a seismograph?
The word “seismograph” itself comes from Greek and directly means “record”, “earthquake”. The oldest seismograph was made in ancient China. It was a large bronze bowl, which was held on eight dragons, in the open mouth of each dragon was a ball. Inside the bowl was suspended a pendulum attached to a rack, which was mounted rigidly on the base of the plate lying on the surface of the earth. When the oscillation occurred, the pendulum hit the wall of the bowl, and a ball fell out of the mouth of the dragon, falling into the mouth of a metal toad, located below this structure. Such a device could record vibrations beyond 600 km from its location.
Principle of operation
The principle of operation of a seismograph is based on the transmission of vibrations to objects installed on a plot of the earth's crust. When one plate of the earth's crust is found on another, a huge amount of energy is accumulated, when it is released, a concussion occurs.
What is a seismograph? Modern devices consist of a pendulum suspended on a thread and fixed to a rack, firmly standing on the ground. At the end of the pendulum there is a feather, which, when oscillating, will draw the amplitude of the strain value. A drum with paper on which the earthquake process will be displayed is also installed firmly on the ground. When an earthquake occurs, the pendulum due to inertia remains in place, and the drum with the paper makes oscillating movements, drawing the value of the energy released during the earthquake. Modern devices are able to control even minor changes that do not carry destruction.
What is an animal seismograph? Their body is designed so that the slightest changes in the atmosphere and the state of the earth's surface within a radius of several kilometers cause them anxiety. The law of self-preservation is triggered, and they leave the dangerous territories. The most sensitive to the earthquake phenomenon are considered to be related to the species of amphibians and reptiles, that is, snakes, frogs, lizards.
Specifications
Modern seismographs are able to determine and measure the amplitude of oscillations in three planes. Measuring vibration velocity, seismographs have a measuring frequency range from 0.3 to 500 Hz, with a vibrational velocity measuring range from 0.0002 to 20 mm / s. Seismographs are both portable and stationary. The latter are large-sized and installed specifically once and for the entire service life. Portable can be reinstalled in a specific place depending on the terrain. All modern models are equipped with software interfaces and directly transfer all their measurements to the database on a computer.
Application features
What is a seismograph and where to install it? It is placed in potentially hazardous areas where manifestations of fluctuations in the earth's crust are possible. Portable seismographs are installed in areas of mining or underground mining in order to avoid human casualties by preventing earthquakes and evacuating workers. During installation, it should be borne in mind that the device can give serious errors if it is installed near roads where heavy equipment can travel.