What kind of stress causes earthquakes?

Earthquakes are caused by the sudden release of energy in Earth's crust that creates seismic waves. Tectonic stress, which is the result of the movement of tectonic plates, can cause earthquakes if the plates are locked or stuck and cannot move smoothly past each other. This stress builds up over time and eventually overcomes the friction holding the plates in place, causing them to slip suddenly and releasing the stored energy in the form of seismic waves. This type of stress is often associated with earthquakes that occur along plate boundaries, such as the Pacific Ring of Fire.