An earthquake - shortly the protracted, sudden concussionsof the earth's crust, caused by the variable transferring of themasses of mountain breeds to the bowels of the earth ofEarth, why violation of tensility of mountainbreeds and origin of seismic waves promotes; duringkillerquakes, on a terrene often there are cracks, upcasts,changes, tsunamis; sometimes earthquakes cause largedestructions (for example, in 1988 in Armenia).