The Ring of Fire
Dormant volcanoes
Non-explosive volcanoes will have low concentrations of gas in the magma.
Eruptions at shield volcanoes are almost always non-explosive.
Explosive volcanoes are most common at subduction zones.
Large explosive eruptions are generally characteristic of stratovolcanoes.
Rhyolite caldera complexes are the most explosive volcanoes, although other types of volcanoes can also erupt.
Volcanoes in Japan have explosive eruptions because there is a a magma chamber that has not completely move along the mantle yet so when it erupts it has explosive eruptions.
Shielf volcanoes generally produce "quiet" eruptions. Explosive eruptions are rare.
composite volcanoes
Volcanoes with more viscosity are more explosive.
Explosive types of volcanoes are typically referred to as stratovolcanoes or composite volcanoes. These volcanoes are characterized by their steep sides and explosive eruptions caused by trapped gases and thick, viscous lava. Examples include Mt. St. Helens in the United States and Mt. Fuji in Japan.
There are three types of volcanoes which have different shapes and types of eruptions. * Shield Volcanoes - are low and flat and have small, flowing eruptions. * Composite Volcanoes - are a mixture between shield volcanoes and cone volcanoes, their eruptions are explosive. * Cone Volcanoes - are the tallest and largest volcanoes, and they have VERY explosive eruptions.