How Many Types Of Volcanoes Are There?

There are four major types of volcanoes:

• Lava domes

• Composite volcanoes

• Cinder cones

• Shield volcanoes

Lava Domes

A lava volcano is a circular mound-shaped protrusion formed by the gradual ejection of viscous lava from a volcano. Dome-building eruptions are widespread, especially along convergent plate boundaries. Lava dome formation accounts for around 6% of all eruptions on Earth.

The geochemistry of lava domes can range from basal to rhyolite, with the majority being of intermediate composition (such as Santiaguito, dacite-andesite, present day). The dome form is due to the lava's extreme viscosity, which prevents it from flowing very far.

This high viscosity may be achieved in two ways: through high quantities of silica in the magma or fluid magma degassing. Because viscous basaltic and andesitic domes weather quickly and readily, most surviving domes have high silica content and are composed of rhyolite or dacite.

Composite Volcanoes/Stratovolcanoes

Composite volcanoes, such as Cotopaxi, are made up of alternating layers of lava and tephra. The alternate term, stratovolcano, is derived from the layers (strata). Cotopaxi has the typical form of composite volcanoes, with steep slopes as they approach the volcano's summit.

The slope shift is caused by the build-up of tephra particles near the volcano's vent. Composite volcanoes emit greater viscosity andesitic and rhyolitic lavas that do not flow as far from the vent as basaltic lavas. This leads to smaller-diameter volcanoes than shield volcanoes.

Mt. Fuji in Japan is an exception, as it erupts basaltic lava. According to geology, composite volcanoes form swiftly and survive for a short period. If volcanic activity stops, it might fade away in tens of thousands of years. This is primarily due to the existence of weak pyroclastic eruptive material.

Cinder Cones

Cinder cones are round or oval cones formed by blowing up tiny particles of lava from a single vent. Cinder cones are formed by the accumulation of tiny fragments of scoria and pyroclastics surrounding a vent.

Mt. Capulin and other cinder cones have straight sides and are generally less than 200 m high. The majority are made up of scoria particles (vesicular basaltic lava rock) that were blasted from the volcano as gas-rich magma erupted.

Cinder cones have relatively little strength since they are virtually entirely made up of loose bits. They may be readily and swiftly eroded.

Shield Volcanoes

Shield volcanoes have a central bowl or shield shape with long gentle slopes formed by basaltic lava flows.

These are generated by the eruption of low-viscosity lava, which can travel a long distance from a vent. They do not usually detonate catastrophically. They are more prevalent in marine than continental settings. The Hawaiian volcanic chain is made up of shield cones.