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Submarine volcanoes are underwater vents or fissures in the Earth 's surface from which magma can erupt. Many submarine volcanoes are located near areas of tectonic plate formation, known as mid-ocean ridges. The volcanoes at mid-ocean ridges alone are estimated to account for 75% of the magma output on Earth. [ 1]
Magma that cools slowly within a magma chamber usually ends up forming bodies of plutonic rocks such as gabbro, diorite and granite, depending upon the composition of the magma. Alternatively, if the magma is erupted it forms volcanic rocks such as basalt, andesite and rhyolite (the extrusive equivalents of gabbro, diorite and granite ...
Vulcanian eruptions are a type of volcanic eruption named after the volcano Vulcano. [24] It was named so following Giuseppe Mercalli's observations of its 1888–1890 eruptions. [25] In Vulcanian eruptions, intermediate viscous magma within the volcano make it difficult for vesiculate gases to escape.
The pressure of the magma builds until the blockage is blasted out in an explosive eruption through the weakest point in the cone, usually the crater. (However, in the case of the eruption of Mount St. Helens, the pressure was released on the side of the volcano, rather than the crater. [3]). The release of pressure causes more gas to exsolve ...
Volcanic gases are gases given off by active (or, at times, by dormant) volcanoes. These include gases trapped in cavities ( vesicles) in volcanic rocks, dissolved or dissociated gases in magma and lava, or gases emanating from lava, from volcanic craters or vents. Volcanic gases can also be emitted through groundwater heated by volcanic action ...
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. The process that forms volcanoes is called volcanism . On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and because most of ...
A magma chamber is a large pool of liquid rock beneath the surface of the Earth. The molten rock, or magma, in such a chamber is less dense than the surrounding country rock, which produces buoyant forces on the magma that tend to drive it upwards. [ 1] If the magma finds a path to the surface, then the result will be a volcanic eruption ...
COPENHAGEN (Reuters) -A volcano in southwestern Iceland erupted on Thursday, the meteorological office said, spraying red-hot lava and smoke in its sixth outbreak since December. Livestreams from ...