What makes magma more explosive?
More crystals in the magma enable more gas bubbles to form, and so they make an eruption more explosive. The rate at which pressure is reduced also affects the explosiveness. If magma moves slowly toward the surface, gases in the magma have more time to escape.
What raises the hazard potential of a volcanic eruption?
These gases include sulfur dioxide, carbon dioxide, hydrogen sulfide, and many others. The release of gas can make a volcanic eruption more explosive, and some volcanoes produce large amounts of gas. The gases can pose a variety of dangers to surrounding populations in sufficiently high concentrations.
What character of magma increases its explosive capacity?
Gas Gas gives magmas their explosive character, because volume of gas expands as pressure is reduced.
What causes explosive pressures to build up in a volcano?
If magma is thick and sticky, gases cannot escape easily. Pressure builds up until the gases escape violently and explode.
Which of these magmas produce the most explosive eruptions?
The largest and most violent of all the types of volcanic eruptions are Plinian eruptions. They are caused by the fragmentation of gassy magma and are usually associated with very viscous magmas (dacite and rhyolite).
How does high silica affect magma?
Lava with high silica content is thick and viscous and does not readily flow. Lava rises up toward the surface but is too thick to squeeze through the cracks and fissures in the Earth. As lava continues to rise upward, pressure continues to build.
Which of the following factors associated with huge volcanic eruptions may cause the decrease in the Earth’s average temperature for a few years?
Large eruption columns inject ash particles and sulfur-rich gases into the troposphere and stratosphere and these clouds can circle the globe within weeks of the volcanic activity. The small ash particles decrease the amount of sunlight reaching the surface of the earth and lower average global temperatures.
What determines how strong a volcanic eruption will be?
The amount of dissolved gas in the magma provides the driving force for explosive eruptions. The viscosity of the magma, however, is also an important factor in determining whether an eruption will be explosive or nonexplosive.
What controls the explosiveness of a volcano?
The amount of dissolved gas in the magma provides the driving force for explosive eruptions. The viscosity of the magma, however, is also an important factor in determining whether an eruption will be explosive or nonexplosive.
Which of the following characteristics of magma affects the explosiveness of volcanic eruption?
Viscosity, together with the amount of gas dissolved in magma, can determine the explosivity of the eruption. More viscous magma with volatiles is more explosive than less viscous magma, where gases can bubble out relatively easily.
Which magma composition should lead to the most explosive volcanoes and why quizlet?
More viscous magmas tend to generate more explosive eruptions. List these three magmas in order from most silica rich to least silica rich, based on their compositions: mafic (basaltic), felsic (rhyolitic), intermediate (andesitic). The eruption of what type of magma may produce an eruption column?
Which of the following characteristics of magma mainly affect the explosiveness of volcanic eruption?
Viscosity, together with the amount of gas dissolved in magma, can determine the explosivity of the eruption. More viscous magma with volatiles is more explosive than less viscous magma, where gases can bubble out relatively easily.
Why does more viscous magma produce more explosive volcanoes?
Magmas that are more rhyolitic have a higher gas content. This gas content and relative viscosity leads to the more explosive and violent eruptions that occur at composite volcanoes.
Do volcanic eruptions increase temperature?
Volcanic eruptions of this magnitude can impact global climate, reducing the amount of solar radiation reaching the Earth's surface, lowering temperatures in the troposphere, and changing atmospheric circulation patterns.
Which of the following factors help determine whether a volcanic eruption will be violent or relatively quiet?
The amount of water vapor and other gases present is one factor that determines whether a volcanic eruption will be quiet or explosive.
Which of the following factors help determine whether a volcanic eruption will be violent or relatively quiescent?
Which of the following factors help determine whether a volcanic eruption will be violent or relatively quiescent? It is determined by the primary factors of the magma's Temperature, its Composition, and the amount of Dissolved Gases it contains. The viscosities of magmas increase with increasing percentages of silica.
Which of the following materials from a volcano determines explosiveness?
Gas gives magmas their explosive character, because the gas expands as pressure is reduced. Felsic magmas usually have higher gas contents than mafic magmas.
Which magma composition is most likely lead to an explosive eruption?
Explosive eruptions are favored by high gas content & high viscosity magmas (andesitic to rhyolitic magmas). The explosive bursting of bubbles fragments the magma into clots of liquid that cool as they fall through the air. These solid particles become pyroclasts or volcanic ash.
Which of these magmas tend to produce the most explosive eruptions?
Explosive eruptions are favored by high gas content & high viscosity magmas (andesitic to rhyolitic magmas).
What magma would probably cause the most explosive eruption?
Rhyolitic magma would probably cause the most explosive eruption.
Which of the following factors causes an explosive eruption from a composite volcano?
A volcano's explosiveness depends on the composition of the magma (molten rock) and how readily gas can escape from it. As magma rises and pressure is released, gas bubbles (mainly of water vapor and carbon dioxide) form and expand rapidly, causing explosions.
Which type of magma would you expect to produce the most explosive volcanic eruption?
Explosive eruptions are favored by high gas content & high viscosity magmas (andesitic to rhyolitic magmas). The explosive bursting of bubbles fragments the magma into clots of liquid that cool as they fall through the air.
Which type of magma will produce the most explosive volcanic eruption?
andesitic to rhyolitic magmas Explosive eruptions are favored by high gas content & high viscosity magmas (andesitic to rhyolitic magmas). The explosive bursting of bubbles fragments the magma into clots of liquid that cool as they fall through the air.
How does viscosity affect the explosiveness of a volcano?
Magmas that are more rhyolitic have a higher gas content. This gas content and relative viscosity leads to the more explosive and violent eruptions that occur at composite volcanoes. In general, SiO2 content controls the relative viscosity of a magma. Viscosity is the ability of a liquid to resist flowing.
How do explosive volcanic eruptions affect global temperatures quizlet?
How can large volcanic eruptions cause global temperatures to decrease? As the ash and gasses are spread around the planet they may absorb and scatter enough sunlight to cause the average global temperature of Earth to decrease.
What are 2 important factors that affect the explosiveness of a volcanic eruption?
A volcano's explosiveness depends on the composition of the magma (molten rock) and how readily gas can escape from it. As magma rises and pressure is released, gas bubbles (mainly of water vapor and carbon dioxide) form and expand rapidly, causing explosions.
Which of the following factors helps determine whether a volcanic eruption will be explosive or relatively quiet?
A. The amount of water vapor and other gases present is one factor that determines whether a volcanic eruption will be quiet or explosive.
What magma types produce explosive and effusive eruptions?
Overview. There are two major groupings of eruptions: effusive and explosive. Effusive eruption differs from explosive eruption, wherein magma is violently fragmented and rapidly expelled from a volcano. Effusive eruptions are most common in basaltic magmas, but they also occur in intermediate and felsic magmas.
What causes the most explosive volcanic eruption quizlet?
Silica-rich magma is stiff, and hardens in a volcano's vent and plugs the vent. As more magma pushes up, pressure increases, causing an explosive eruption.
Which of the following characteristics of magma affect the explosiveness of volcanic eruption?
Viscosity, together with the amount of gas dissolved in magma, can determine the explosivity of the eruption. More viscous magma with volatiles is more explosive than less viscous magma, where gases can bubble out relatively easily.