The annual movement of the plates ranges from a couple of centimetres to almost twenty centimetres. The generated stresses and the energy is partly released as earthquakes. Tectonic earthquakes occur due to the release of the stress caused by relative plate motion. The most destructive earthquakes are always tectonic. Volcanic tremors are associated with volcanic eruptions, when magma penetrates the crust and ruptures it.
Volcanic earthquakes are minor or at most moderate in magnitude.
Collapse earthquakes are weak and usually occur in smallish caves, cavities or mines. A cave may collapse by itself or is triggered by human activity such as explosions. Make sure you know the location of the emergency exits and the foam extinguisher. Keep heavy objects on the lower shelves or on the floor away from the exit routes. It is usually safest to stay indoors during an earthquake.