Explaining The Universe on Instagram: "Earthquakes are sudden vibrations or shaking of the ground caused by the movement of rocks deep beneath Earth’s surface. They occur when stress builds up along faults — fractures in the Earth’s crust — until it’s released as seismic energy that travels outward in waves. Most earthquakes happen at tectonic plate boundaries, where plates collide, slide past, or pull away from each other. The point underground where the quake begins is called the focus, and th