Sejsmologi

Sejsmologi, known in English as seismology, is the scientific study of earthquakes and the propagation of elastic waves through the Earth. The field seeks to understand how earthquakes originate and propagate, the structure and composition of the Earth's interior, and the properties of seismic waves as they move through rocks. It encompasses fundamental research on the dynamics of faulting and wave physics, as well as practical applications in hazard assessment, engineering, and subsurface imaging.

Methods and data in sejsmologi rely on observations from networks of instruments that record ground motion. Seismometers and accelerometers measure shaking from distant and near earthquakes, while seismic stations and temporary deployments build comprehensive waveform databases. Analysts extract information such as earthquake location, depth, magnitude, and the characteristics of seismic waves. Key techniques include waveform analysis, seismic tomography, receiver functions, and inverse modeling to image internal structures and to characterize source processes. Global networks and data centers, such as IRIS, the International Seismological Centre (ISC), and national observatories, coordinate data collection and sharing.

History and development of the discipline trace to observations of seismic waves in the late 19th and early 20th centuries. Notable milestones include the identification of the Mohorovičić discontinuity (the Moho) in 1909, which revealed the crust–mantle boundary, the discovery of the outer and inner core boundaries, and the development of magnitude scales such as the local magnitude (ML) and the moment magnitude (Mw). Today sejsmologi is a data-driven, international field that supports earthquake hazard assessments, informs engineering design, and enhances subsurface imaging for natural resources and geotechnical investigations.