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What Are Some Facts About the Cinder Cone Volcanoes?

Scientists who study volcanism subdivide all volcanoes into four groups. They use the volcanoes' size, shape, composition and structure to make this classification. The three most familiar volcano types are the cinder cone, the stratavolcano (also called a composite volcano) and the shield volcano. A fourth, less familiar classification, is called a lava dome.

Size and Shape
- Cinder cones are relatively small, especially when compared to shield volcanoes, such as those that make up the Hawaiian Islands. Cinder cones range in size from just a few feet to more than a thousand feet tall. They are characterized by steep, straight sides that form an obvious cone shape; and have a well-defined circular or oval crater at their crest. Most are nearly circular at the base, although they may be slightly elongated parallel to the prevailing wind direction or along a fissure.
Occurrence
- Cinder cones are known from around the world, almost anywhere there is active volcanism. They may occur singly or in groups. Typical settings for cinder cone growth include along fissures and other zones of weakness in flood basalts, in active fault terranes and as "parasitic" cones on the sides of larger shield volcanoes and stratavolcanoes. Many, although not all, cinder cones have formed as the result of a single short-lived eruption.
Structure
- Cinder cones are built up, not by lava flows, but from particles of lava that cooled in midair after being ejected in an explosive eruption. This particulate material is collectively called tephra. Explosive eruptions, such as those that build cinder cones, result from magma that contains high amounts of water vapor and other gases, or from magma whose chemical composition makes it thick and pasty, thus unlikely to flow. After the tephra is blown into the air, it falls back to earth, building a cone-shaped pile of cinderlike material around the center of the eruption.
Examples
- Cinder cones are common through much of the western United States and Mexico. Some large and well-known cinder cones in North America include Sunset Crater just outside Flagstaff, Arizona, and Parícutin, near Mexico City. The mid-20th century eruption that created Parícutin's was observed by scientists from around the world.
  
  A cinder cone on the island of Stromboli, between Sicily and Italy, has been erupting at regular intervals for centuries. Cinder cones as small as a few feet tall can be found on the slopes of larger shield volcanoes in Hawaii and Central America.

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