Volcanoes are important for many reasons, including benefiting nearby plants with nutrient-rich ash, providing rare species with habitats that are inaccessible to humans and livestock, and enriching the atmosphere with gases, according to Oregon State University. The Earth's life, water and atmosphere would not exist without volcanoes.Continue Reading
Volcanic gases released from vents since the Earth's formation are responsible for the atmosphere and oceans, which led to the evolution of life, according to the United States Geological Survey. Duke University states that while meteorites and comets also brought gases that helped build the atmosphere of the Earth, volcanic activity was probably the primary source of these gases.
Over 80 percent of the surface of the Earth comes from volcanic activity. Volcanic eruptions produce everything from plains and hills to mountains and plateaus. Volcanic deposits are also used as building materials. Basalt and diabase, both produced by volcanoes, are used by humans for many things, including concrete, roofing and the construction of nuclear reactors.
Volcanoes continue to play an important role by adding to the Earth's water supply and forming new islands. Volcanic eruptions may slow climate change by releasing aerosols that help block sunlight into the Earth's stratosphere, according to a Nature Geoscience study mentioned in Time magazine.Learn more about Volcanoes
Composite volcanoes, also known as stratovolcanoes, are formed by the gradual deposition of alternating layers of volcanic lava and ash. When volcanoes erupt, emitting lava that flows very slowly, the lava cools and hardens, forming conical shaped composite volcanoes after multiple eruptions over a span of hundreds of years.Full Answer >
Composite volcanoes, one of the two main types of volcanoes along with shield volcanoes, are composed of alternating layers of lava and ash or other volcanic debris. These volcanoes are usually cone shaped with steep sides that are built up by multiple eruptions over hundreds or thousands of years.Full Answer >
Steep-sided volcanoes, or stratovolcanoes, are primarily made from multiple layers of cinders and ash that were laid down during past eruptions. According to Oregon State University, stratovolcanoes are distinct from shield volcanoes due to their high altitude and steeply graded sides.Full Answer >
According to the UCSB Geology Department, a volcanic eruption is defined as a volcanic event resulting in the emission of gases, lava, ash or other material from a volcano. These can manifest as a single eruptive pulse, an eruptive phase or an eruptive episode.Full Answer >