#seismology

• Anaseism — A seismological phenomenon consisting of the initial upward or push movement of the ground at the reception point (at the seismic station) upon the arrival of the primary seismic wave (P-wave), indicating a compressional motion away from the hypocenter. This structural dynamic, opposite to kataseism, is essential for researchers in determining the focal mechanism of an earthquake and for understanding the type of tectonic fault activated.
• Aseismic — Not seismic; a geographical region or zone characterized by the absence of earthquakes or by the occurrence of tectonic movements of negligible intensity. In structural engineering, the term is sometimes used (as a variant for antiseismic) to describe elements designed to withstand seismic shocks, though in geology it exclusively indicates a lack of seismic activity.