Tectonic movements are responsible for the shape and formation of the earth's crust. The word tectonic is often used to describe occurrences that are large in scale and have a significant impact on the environment. Some synonyms for tectonically include geologically, structurally, and foundationally. Other possible synonyms could be seismic or earthshaking. Tectonically may also be interchangeable with the term plate tectonics, which describes the motion of the large plates that make up the earth's crust. Regardless of the specific term used, when something occurs tectonically, it means that it has a profound and long-lasting impact on the surrounding area.