which characteristics of magma mainly affect the explosiveness?
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Three characteristics of magma that mainly affect the explosiveness of a volcanic eruption include gas content, viscosity, and temperature. The gas content of magma mainly affects the explosiveness of a volcanic eruption because the volume of gas expands as the pressure is reduced.
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Magma composition determines both eruption type and volcano type. Composite cones are built of felsic to intermediate lava and shield volcanoes of mafic lava. Cinder cones are made of small fragments of a variety of compositions usually from a single eruption.
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Volcanic eruptions may be subtle or explosive and can produce dangerous lava flows, poisonous gases, and flying rocks and ash. Many volcanic eruptions are also accompanied by other natural hazards, such as earthquakes, landslides, debris flows, flash floods, fires and tsunamis.
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In general, the more felsic the magma the greater the volatile content. So mafic/basaltic volcanoes are fairly quiescent, intermediate/andesitic volcanic eruptions are moderately explosive, and felsic/rhyolitic volcanoes may be extremely explosive.
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In general, the more felsic the magma the greater the volatile content. ... Their high volatile content makes them potentially highly explosive. Shield Volcanoes. Because mafic lava is low viscosity, when it erupts from a volcano it flows downslope away from the vent, gradually cooling and crystallizing.
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Volcanoes have distinctive features: magma chamber - this is where the molten rock is stored beneath the ground. main vent - this is the channel through which magma travels to reach the Earth's surface. secondary vent - some magma may escape through the side of the volcano, particularly if the main vent becomes blocked.
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The two most notable are obsidian and dunite. Obsidian is volcanic glass which erupts as a lava flow. Most obsidian is felsic in composition, yet typically it will have a very dark color (dark brown to black). Dunite has an ultramafic composition yet is apple green to yellowish green in color.
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Image courtesy of USGS. There are two predominant types of volcanic eruptions: Effusive eruptions – magma rises through the surface and flows out of the volcano as a viscous liquid called lava. Explosive eruptions – magma is torn apart as it rises and reaches the surface in pieces known as pyroclasts.
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A magma's viscosity is largely controlled by its temperature, composition, and gas content (see downloadable programs at the bottom of this page). The effect of temperature on viscosity is intuitive. Like most liquids, the higher the temperature, the more fluid a substance becomes, thus lowering its viscosity.
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The primary factors that determine whether a volcano erupts violently or quietly include magma composition, magma tempera- ture, and the amount of dissolved gases in the magma.
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Volcanoes erupt when molten rock called magma rises to the surface. Magma is formed when the earth's mantle melts. ... If magma is thick, gas bubbles cannot easily escape and pressure builds up as the magma rises. When the pressure is too much an explosive eruption can happen, which can be dangerous and destructive.
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The high temperatures and pressure under Earth's crust keep magma in its fluid state. There are three basic types of magma: basaltic, andesitic, and rhyolitic, each of which has a different mineral composition. All types of magma have a significant percentage of silicon dioxide.
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Would quiet eruptions or explosive eruptions be more likely to increase the height of a volcano? ... Quiet eruptions, because they usually build up layers of lava whereas explosive eruptions often blow up the top of a volcano, decreasing its height.
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There are four basic characteristics to look at; ignitability, corrosivity, reactivity, and toxicity. Ignitability – According to the EPA, “Ignitable wastes can create fires under certain conditions, are spontaneously combustible, or have a flash point less than 60 °C (140 °F).
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What factors determine the force of a volcanic eruption? the amount of gas dissolved into the magma, its temperature, and how thick the magma is.
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['The materials associated with a volcanic eruption.', 'include lava flows (pahoehoe and aa flows for basaltic lavas), gases (primarily in the form of.', 'water vapor), and.', 'pyroclastic material (pulverized rock and lava fragments blown from.', "the volcano's vent, which include ashes, pumice.", ', blocks,', 'and bombs).']
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When magma is ejected by a volcano or other vent, the material is called lava. Magma that has cooled into a solid is called igneous rock. Magma is extremely hot—between 700° and 1,300° Celsius (1,292° and 2,372° Fahrenheit).