Types of Volcanoes

Acid domes form when thick, acidic lava pushes up from underground but solidifies quickly before flowing far. They're tall with steep, rounded slopes that have a convex shape. You'll typically find these domes near larger composite volcanoes. Famous examples include Puy de Dome in France and Mount Pelee in Martinique.

Composite volcanoes are built from alternating layers of lava flows, volcanic ash, and cinders. They feature a central conduit system where material exits through a vent. These volcanoes stand tall with steep, symmetrical sides and usually have a crater at the summit. Lava can flow from breaks in the crater wall or through fissures on the sides. Mount Fuji in Japan and Mount St. Helens in Washington are classic examples.

Ash and cinder cones form when lava erupts from a single opening, breaks up in the air, and falls as cinders around the vent. These circular or oval cones have steep sides with a bowl-shaped crater at the summit. They're relatively small, rarely exceeding a thousand feet in height. Paricutin in Mexico and Lava Butte in Oregon demonstrate this type perfectly.

Did you know? The shape of a volcano can tell scientists a lot about how dangerous it might be! Steep-sided volcanoes like composite types tend to have more explosive eruptions than gentler-sloped shield volcanoes (not mentioned here).