Volcanism corresponds to all phenomena related to the ascent of magma or molten rocks from the interior of the Earth to the earth's surface. It is one of the main manifestations of the internal energy of the terrestrial globe and mainly affects the unstable areas of its crust. Volcanoes are points of relief that directly communicate the earth's surface with the inner layers of the crust, where, due to the high temperature present, the rocks are in a state of fusion.
During periods of activity, the weakest areas of the Earth's crust break due to high temperatures and pressure, thus causing an eruption process, where volcanoes expel a large amount of materials, either liquid or semi-fluid (lava), solid (ashes, volcanic bombs, small particles or gravel) and gaseous, the latter can be very varied and usually contain sulfur, chlorine, carbon, oxygen, nitrogen, hydrogen and boron.
Volcanoes develop in mountain ranges in the process of creation, as well as in dislocated basements, and not in sedimentary basins, so that volcanism is associated with tectonic zones. For magma to rise, it needs to be close enough to the surface to take advantage of the area of dislocations. There must also be an imbalance between pressure and temperature.
According to the nature of the eruption, volcanic activity can be classified into various types: Hawaiian, Pelean, Vulcan, Strombolian, Vesuvius, Plinian, and Icelandic.
It should be noted that volcanism is not an exclusive phenomenon of our planet; it is universal and cosmic. In the solar envelope there are spots where flares of volatile materials come out that reach many thousands of kilometers in height. Countless extinct volcanic craters are observed on the Moon and intense volcanic activity is confirmed on Mars. A large number of aeroliths and meteorites are attributed to volcanic eruptions that occurred in other stars.
