Which of the following is caused by the movement of the tectonic plates?

Earthquakes are caused by the movement of tectonic plates. The Earth's lithosphere is divided into plates that slowly shift due to underlying currents. When these plates interact, stress builds up along their boundaries. Earthquakes happen when the accumulated stress exceeds rock strength, resulting in seismic waves that shake the ground. 

However, tectonic plate movement does not directly cause storms or floods. Storms are caused by atmospheric conditions, while floods can result from heavy rainfall, river overflow, or dam failures. While tectonic plate movement indirectly affects weather patterns, earthquakes are the primary geological event associated with their motion.

Hence, "Earthquakes" is the correct option.