Volcanoes: The Science Behind Eruptions, and Predicting Them
May 3, 2023
Sylvie Pagovich
10th Grade
Ramaz Upper School
Volcanoes are defined as an opening in the crust of a planet or moon. These openings allow molten rock, heated gasses, and other substances to erupt. Volcanoes can be found in many places: they can be found on land or in the ocean and even on other planets. A volcano is formed as layers of rock and ash accumulate from numerous eruptions and is frequently shaped like a hill or a mountain. Volcanoes can either be active, dormant, or extinct. An active volcano is a volcano that has recently erupted and will erupt again. A dormant volcano is a volcano that hasn’t erupted for a while and will erupt again in the future. For example, the Yellowstone volcano last erupted 700,000 thousand years ago. Although it has remained dormant since then, the volcano is expected to erupt again in the future. On the other hand, extinct volcanoes are volcanoes that will never erupt again.
Volcanoes erupt when magma rises to the surface. Magma is created from the melting of Earth’s mantle. Volcanic eruptions can also take place as a result of tectonic plate activity. Tectonic plates are solid and rocky and they make up Earth’s surface. These tectonic plates aren’t static; they are constantly sliding towards, away from, or next to one another. (Friction from tectonic plates is actually what causes earthquakes too!) When the plates slide under one another, the water that is trapped escapes with a lot of pressure, producing heat to melt rock, which then forms magma. As the chamber of the volcano fills up with more magma, the pressure inside increases. Cracks frequently appear above when the upward pressure created by the rock below the chamber is greater than the downward pressure produced by the rock above the chamber. Eventually, the pressure from above can force the magma through fissures and vents on the surface, turning it into lava.
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(Image credit: YourDictionary)
There are many different types of volcanoes. One type is a Cinder Cone Volcano, a volcano that is made of solid lava from previous eruptions. A large explosion sends gas, ash, and molten rocks flying into the air. The rocks pile up around the vent as they crash to the ground after rapid cooling in the air and falling to the surface of the earth. They build up into a little cone of cinder that can rise to a thousand feet above the surrounding terrain. Repeated cinder and lava flow eruptions from the same vent may result in the formation of a stratovolcano (combined volcano). This is a volcano made of repeating layers of lava flows, volcanic ash, cinders, blocks, and volcanic bombs. There is also a Shield Volcano, which is built from lava fluids. Lava pours out of vents either from the top or from fractures. As the lava overlaps, it creates a gently sloping dome shape that can appear as a warrior's shield.
Scientists have recently been working on creating new technologies to help them predict when volcanic eruptions will take place. In the past, scientists would use Earthquake data, the shake that comes beforehand, measurements of the deformation of the ground that happens when magma rises, and changes in gravity and the magnetic field to help them predict when the volcano would erupt. Scientists have more recently started focusing on trying to find out where the magma is located. They do this by searching for microscopic, carbon dioxide-rich fluids encased in cooled volcanic crystals. In 2021, they figured out how to use these crystals to determine the depth of the magma. Through this, they can learn more about volcanoes to better understand them and prepare for the future.
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