Basic geophysics / Основы геофизики

Geophysics is the study of the physics of the earth, its surface, interior, and surrounding environment in space. An important part of geophysics is seismology. Seismic waves are vibrations that travel through the earth’s interior or along its surface. Seismology is the study of how seismic waves can be used to determine the interior structure of the earth. Earthquake seismology is concerned with the structure of the entire earth, whereas exploration seismology deals with only the upper few kilometers of the earth’s crust. In earthquake seismology, the source is passive, because the signals are earthquakes, which naturally occur within the remote medium (the subterranean earth). In exploration seismology, the source is active, because the signals are generated intentionally in the accessible medium (the surface or near-surface of the earth). <...>