Volcanoes exist all around the world. They can be very dangerous or unharmful. Some may seem unharmful because of their appearance, but they really are harmful to humans and wildlife. Volcanoes occur when two tectonic plates collide or, when there is a hot spot in the crust and constructive forces build a volcano. There are two types of volcanic flows pyroclastic and mud flows. Pyroclastic volcanoes occur when the amount of magma in the chamber collects and the pressure increases causing the volcano to erupt. Mud flows are kind of like pyroclastic accept the lava in the chamber doesn't collect and cause an eruption it just flows out the top of the volcano.
Mount Etna is located on the island of silicon,