Force Quake was a very effective Dark Force power used only by the most powerful of Sith Lords. The power required a great amount of force to use. When the power was used, the force user would build up a large mass of dark Force energy under a certain area of the ground. When it got to a critical point, the power was released causing a massive ground explosion that destroyed or severely damaged any thing in range. The only known user of the power is Darth Casto.