A stratovolcano is characterized by its explosive eruptions, making it one of the most dangerous types of volcanoes. Also known as composite volcanoes, they typically have a steep profile and are formed by alternating layers of lava flows, ash, and volcanic rocks. The eruptions of stratovolcanoes can be quite violent due to their thick, viscous lava, which can trap gases. When the pressure builds up sufficiently, it leads to explosive eruptions that can project ash and pyroclastic flows over large areas. Famous examples of stratovolcanoes include Mount St. Helens in the United States and Mount Vesuvius in Italy.