Teknik Gempa Earthquake Engineering D-III Teknik Sipil Jurusan Pendidikan Teknik Sipil dan Perencanaan FT UNY • Is a sudden motion or trembling in the Earth. The motion is caused by the quick release of slowly accumulated energy in the form of seismic waves. Most earthquakes are produced along faults, tectonic plate boundaries, or along the mid-oceanic ridges. What is actually happen? Earth Crust Earth tectonic plate Earthquake events organized according to depth (yellow (shallow) = surface to 25 kilometers below the surface, red (intermediate) = 26 to 75 kilometers below the surface, and black (deep) = 76 to 660 kilometers below the surface).