Volcanoes eject lava to the surface

Volcano is a geological form where the lava comes to the surface of the Earth's crust. It is often the mountains, but there are submarine volcanoes, which significantly affects the formation of the Earth's relief. Most often found on the edges of the inter-plate. They can be active or inactive. That depending on it's eruptions and tectonic activity in it's vicinity.

The most notable part is the volcanic dome. that is constantly increasing. At the top of the dome is a crater and the connection between the crater and the fireplace makes the volcanic channel. The penetration of magma can happen for several reasons. This are tectonic influences and changes in deep pressure that is pushed. High temperature is from 600 to 1200 ° C. Temperature increases the mobility of the magma and melted rocks. For instance, due to gases and vapors that increase the buoyancy of the magma. Magma that moves on the Earth's surface is called lava.

Active volcanoes on Earth form a zone. As a matter of fact, the most active zone is the one that surrounds the Pacific Ocean. It's also called Pacific fiery circle. After this, the area along the Central Atlantic spines. Perpendicular to these two zones provides the Mediterranean area, from the US to the Eurasian ditch or cracks, where is recorded a large activity with a lot of small volcanoes, but also some that are a little higher (Kilimanjaro). In the vicinity of the area, it's very rich in minerals and thermal springs. The soil is very fertile, but to live near the volcano is very dangerous.

There are also underwater volcano. In fact, they often create new islands (Hawaii). In addition, it should be mentioned, Maunu Kew, volcanic mountain in Hawaii. It is measured from the bottom of the Pacific Ocean, 10.203m high, which is about 2.5 kilometers over Mount Everest.

Of course, science is called volcanology.

Lava can break out to the surface in two ways:

- Pouring - magma is ejected slowly and evenly. Thats why occur the basalt caps. USA, Dean peninsula, Kamchatka, Iceland - so-called Hawaiian type volcano. The type of eruption occurs in the case of basic magma, with a small amount of volatiles.
- Eruption - explosive. It's due to large amounts of accumulated gases and water vapor, accompanied by earthquakes. There have been cases of catastrophic consequences for the environment. Asian type volcanoes. For example, it occurs in the case with a lot of volatile magma, acid type.

Besides lava can break out and pyroclastic material:

- Bombs - bigger chunks of lava that when cooling receive a spindle-shaped form
- Blocks - crushed pyroclastic material that can weigh several thousand tons
- Tuff - ashes mixed with water
- Lapi - hot stones the size of gravel

The activity is often accompanied by side effects, outbreaks of water vapor, various gases and chemical compounds.

Fumarole are holes from which water vapor is ejected. From solfatara is ejected hydrogen-sulfide H2S. Mofetil is hole from which is ejected carbon dioxide CO2. Such areas are often accompanied by thermal and mineral springs. Geysers are holes with high pressure from which hot water and steam is ejected. The most famous geyser is the one in Yellowstone National Park (Old Faithful).

Volcanoes can be classified according to their characteristics:

- Stratovolcanos - with "layered" structure resulting alternating lava flows and ash
- In the form of a shield - that is because of the outbreak of lava obtain appearance shield
- Supervolcanos - which are very large and have a potentially great destructive power and influence on the environment