Seismografit

Seismografit, commonly referred to as seismographs, are instruments used to detect and record ground motion caused by earthquakes, volcanic activity, and other vibrations of the Earth. They provide detailed records, or seismograms, that show how the ground moves over time.

How they work

Most traditional seismographs rely on an inertial mass and a moving frame. As the ground shakes, the frame moves while the mass tends to stay at rest due to inertia. The recording system translates the relative motion between the frame and the mass into traces on a rotating drum or a digital signal. Modern systems often use digital sensors that convert ground motion directly into electronic data, which can be processed and transmitted in real time.

Types and components

Seismographs can be analog or digital. They typically measure three components: vertical motion, and two horizontal directions (often north-south and east-west). Seismometers are the sensors, while seismographs refer to the whole recording instrument. Instruments are categorized by their frequency response: broadband (recording a wide range of frequencies), short-period, and long-period, each suited to different seismic phenomena. Seismographs may be part of local stations or integrated into large networks that share data globally.

History and networks

The modern seismograph evolved from enhancements in the late 19th and early 20th centuries, with key developments attributed to researchers who improved sensitivity and reliability. Today, global networks such as the Global Seismographic Network collect continuous data from hundreds of stations around the world, supporting earthquake localization, magnitude estimation, earth structure studies, and compliance monitoring for nuclear tests. Seismographs remain essential tools in seismology, disaster preparedness, and geophysical research.