The name given to a volcano that is made up of layers of volcanic ash and that has a steep, conical shape is a stratovolcano. These volcanoes are also known as composite volcanoes due to their layered composition of lava, ash, and other volcanic materials. Stratovolcanoes are characterized by explosive eruptions caused by the buildup of gas within the volcano, which can result in pyroclastic flows, ash fall, and lava flows. Examples of stratovolcanoes include Mount Fuji in Japan, Mount Vesuvius in Italy, and Mount St. Helens in the United States.