Volcanism that produces explosive eruptions of ash, cinders or other fragmental products ejected under the force of expanding volcanic gases is known as explosive. The eruptions of Mt. St. Helens in 1980, Mt. Pinatubo in 1991, and Chile's Chaiten Volcano in 2008 are familiar Earth-based examples.
This type of volcanism is common on Io, and is responsible for the production of the myriad diffuse circular/ring-shaped deposits of various colors (red, yellow, black, white) that mottle the surface of Io. The numerous volcanic plumes of gas and fine particles that have been imaged above the limb (edge) of Io by the Voyager, Galileo, and New Horizons missions are snapshots of explosive volcanism in action.
To open a new window that describes the materials and procedures necessary to create a simple and inexpensive model of this type of eruption, click on the "Explosive Volcano Model" link at the left.
Volcanism that produces oozing lava flows, rather than explosive eruptions, is known as "effusive". The basaltic shield volcanoes of Hawaii are familiar examples of effusive volcanism.
To open a new window with an exercise from the Lunar and Planetary Institute that allows students to build and explore a simple model of this type of volcanism (also found on Io), click on the "LPI Make a Volcano Exercise" link at the left.
Created 30 April 2008