Cinder cone volcanoes form when high temperatures and pressure melt rock deep inside the Earth. Once a large amount of magma forms, it rises until it reaches the surface, creating an eruption.
Although there are several types of volcanoes, cinder cones are the most common. These small volcanoes, also called scoria cones, Older volcanoes have gentle slopes, while volcanoes that have been active in recent geological times – the last 50,000 years – have steeper slopes. These volcanoes tend to have deep craters. Many are symmetrical, but some are asymmetrical because of where the lava builds up, or because of an eruption on the side of the volcano.
The type of eruption that forms cinder cone volcanoes is called Strombolian. This type of eruption usually produces a column of basalt only a few hundred meters high.
Many cinder cone volcanoes only erupt once. Some cinder cones are linked to larger, nearby volcanoes. Others are located on their own in geological formations called basalt fields.
The most active cinder cone volcano is Cerro Negro, located in Nicaragua. It has erupted more than 20 times since it formed in 1850. The latest eruptions occurred in 1992 and 1995.
Cinder cones are found in the United States in Hawaii, New Mexico, Arizona, California, Oregon and Alaska.