Explaining The Universe on Instagram: "Follow (us) @ExplainingTheUniverse to learn something NEW every day 🧠💫 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.