There are four primary types of volcanoes, including cinder cone volcanoes, shield volcanoes, composite volcanoes and lava domes. A volcano is defined as a chimney or a vent that takes molten rock from the surface of the Earth. The molten rock is referred to as magma and once magma erupts, it is called lava. A volcano is determined to be extinct once it remains dormant for over 10,000 years.
Cinder Cone Volcano
This is considered to be the simplest of all of the volcano types. Blobs of congealed lava and particles are what makes up a cinder cone. When the lava ejects, it does so from a single vent and it is violently blown into the air. The lava breaks apart and develops into small, solid fragments that are referred to as cinders, hence the name of the volcano. These are seen in numerous volcanic terrains, including in western North America.
If you have read a lot about the volcanoes in Hawaii, you are familiar with the shield type of volcano. This volcano can be massive, spanning tens of thousands of feet into the air and hundreds of miles across. The smaller islands that make up Hawaii are basically massive shield volcanoes and the big islands usually have at least one present, such as Mauna Loa, which is located on the main island of the state. The lava in these volcanoes is almost entirely frozen.
This type of volcano is made up of steep slopes and it typically consists of hardened layers of tephra, volcanic ash, lava and pumice. It is the most common type of volcano that you will find on Earth. While they have been discovered one Mars, none have been found elsewhere in the solar system.
This type might also be referred to as a volcanic dome and they come in a wide array of sizes and shapes. Viscous magma is what makes up this type of volcano. The lava usually accumulates around the vent of the volcano instead of erupting explosively into the air.
All of these volcanoes are considered to be active when they are erupting lava, generating seismic activity or releasing gas. It is important to note that even if a volcano is classified as dormant, this does not mean that it will not erupt again. Only when it is considered to be extinct do scientists not expect it to erupt again.
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