Shaking of the Earth is a term used to describe the phenomenon known as seismology, which is the study of earthquakes and seismic waves. Seismology is often abbreviated to SEISM, which is the answer to the crossword puzzle. Earthquakes are caused by the movement of tectonic plates, which can cause the ground to shake and cause destruction. Seismologists study these events in order to better understand the causes and effects of earthquakes.