The term volcano is used to describe one of the many ways in which the planet's internal energy manifests on its surface. Volcanoes are structures that form on the Earth's surface as a result of the accumulation of materials from its interior. They often exhibit activity, expelling gases or materials such as lava, ash, and rock fragments. Many people wonder how a volcano is born and how it is evolving.
In this article we tell you everything you need to know about how a volcano is born, its characteristics and the types of volcanoes that exist.
How a volcano is born
In simpler terms, volcanoes could be described as formations on the Earth's surface that are created by the accumulation of materials from the planet's interior and are prone to exhibit activity by expelling various materials.
Volcanoes can originate in various places. These locations include regions where two tectonic plates converge and one slides beneath the other (known as subduction or convergence zones). They can also originate in plate splitting (divergence) zones, where plates move apart, moving in opposite directions, and molten material from the Earth's core rises to the surface, creating a new crust.
Finally, volcanoes can arise in hot spots, which are areas that are not joined with a plate boundary. Instead, they represent deep structures of molten rock rising to the surface.
When tectonic plates converge, the resulting volcanoes are created by the subduction of one plate beneath another. This can occur between oceanic plates or between an oceanic plate and a continental plate. As the plate descends, reaches a depth of approximately 100-150 km, where it finds a layer of semi-molten and flexible rock known as the mantle. This process creates ocean trenches and is responsible for the formation of volcanoes.
In a certain place, an increase in temperature and pressure occurs, which causes alterations in the minerals and chemicals present. As a result of these changes, rocks in the mantle fuse, leading to the creation of new magma drops. The density of this magma is lower than that of its surroundings, which allows it to rise to the outermost layer of the Earth, the crust. When you reach the crust, The magma accumulates forming what is known as a magma chamber. To reach the Earth's surface, magma can take advantage of fractures or fissures, which will eventually cause an eruption.
Geology and volcanism
The Earth's crust is divided into tectonic plates, which move and shift over time due to the underlying movement of the planet's mantle. These are solid slabs composed of the Earth's crust and the upper mantle. They continually move above the asthenosphere, a region of the upper mantle that is relatively viscous.
ocean trenches They are deep, narrow depressions on the ocean floor. These are the deepest parts of the ocean and are formed when one tectonic plate is pushed under another plate, creating a steep slope.
Volcanism refers to the process by which molten rock, ash and gas are released from the Earth's crust. It can occur in a variety of forms, including explosive eruptions, effusive eruptions, and volcanic vents. The frequency and intensity of volcanism can vary depending on factors such as tectonic activity, magma composition, and the presence of water. Despite the potential dangers associated with volcanic activity, volcanism plays a critical role in the formation of new land masses and the cycling of important minerals and gases in Earth's atmosphere.
Pacific Ring of Fire
The Pacific Ring of Fire is a term used to describe the area surrounding the Pacific Ocean that is characterized by frequent volcanic eruptions and seismic activity. It is a horseshoe-shaped region that It extends for more than 40.000 kilometers and covers the western coast of North and South America, the eastern coast of Asia and the Pacific islands. The region is known for its high concentration of active volcanoes and earthquake-prone zones, making it a challenging but fascinating subject of study for both geologists and seismologists.
The appearance of volcanism in areas of convergent tectonic plates facilitates the formation of a series of volcanoes known as a "volcanic arc." This alignment of volcanoes is parallel to the place where the two plates converge and can be observed at distances that They range between 200 and 300 km from the oceanic trench, with a variation that depends on the angle of subduction.
Continental arcs are chains that occur in the continental crust. An example of these arcs are the Andean volcanoes, which belong to the Pacific Ring of Fire, a region known for this type of volcanism and high levels of volcanic activity. Volcanoes in this group emit magma of medium to high viscosity, with temperatures ranging between 700-950°C and low fluidity, in addition to a large amount of gas.
They can also generate major eruptions that produce lava, rock fragments and ash. The Chile-Argentina volcanoes exhibit this type of behavior and are caused by the subduction of the Nazca oceanic plate beneath the South American continental plate.
Aspects about how a volcano is born
Volcanic arcs can form in oceanic environments, resulting in a series of volcanic islands or island arcs. Eruptions of very fluid magma often occur on these islands, which Initially it is very hot and has a temperature ranging between 950 and 1200 degrees Celsius. Over time, this magma builds up on the ocean floor and forms shield-like structures. Due to the depth at which this activity begins, volcanic cones must expel a significant amount of lava before emerging above sea level to form islands.
The appearance of these important volcanic structures suggests that the magma has encountered significant obstacles on its journey to the surface, causing its viscosity to increase. As a result, the magma that eventually reaches the surface has a greater tendency to produce explosive volcanic eruptions. Two examples of island arcs can be seen in the countries of Japan and the Philippines.
I hope that with this information you can learn more about how a volcano is born and its characteristics.