Types of Volcanoes

Shield Volcanoes

Large, slowly erupting volcanoes are called shield volcanoes. They are formed by the eruption of low-viscosity lava that can flow a great distance from a vent, but not generally explode catastrophically. Since low-viscosity magma is typically low in silica, shield volcanoes are more common in oceanic than continental settings.

Submarine Volcanoes

Underwater volcanoes are called submarine volcanoes. They are common features on the ocean floor. Some are active and, in shallow water, disclose their presence by blasting steam and rocky debris high above the surface of the sea. Many others lie at such great depths that the tremendous weight of the water above them prevents the explosive release of steam and gases. Pillow lava is formed under the water after submarine volcanic eruptions. Pillow lava consists of big, round lumps of rocks that look like huge pillows.

A Cinder Cone

A cinder cone is a steep, conical hill formed above a volcanic vent. They are the result from eruptions that erupt mostly small pieces of lava called cinders. These can be relatively short-lived eruptions that produce a cone-shaped hill perhaps 30 to 400 meters high.

Strato Volcanoes

A large, steep-sided volcano made from many layers of lava and rock pieces is called a strato volcano. Stratovolcanoes are also known as composite volcanoes, created from several structures during different kinds of eruptions. Strato/composite volcanoes are made of cinders, ash and lava. Cinders and ash pile on top of each other, lava flows on top of the ash, where it cools and hardens, and then the process begins again.

Subglacial Volcanoes

Subglacial volcanoes form underneath icecaps. They are made up of flat lava which flows at the top of extensive pillow lavas. When the icecap melts, the lavas on the top collapse leaving a flat-topped mountain. These volcanoes are also called table mountains.