Which of the following increases the viscosity of magma quizlet?
The viscosity of magma increases with: high % silica and cooler temperatures.
Which type of plate boundary generates the greatest quantity of magma?
The greatest volume of magma is produced along the oceanic ridge system in association with seafloor spreading.
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 one of the following magmas shows the highest magma viscosity?
The magma that has the highest viscosity is rhyolitic magma. One of the main reasons for the high viscosity in rhyolitic magma is that it contains a…
Which composition of magma is most likely to cause highly explosive eruptions?
As a general rule, therefore, nonexplosive eruptions are typical of basaltic-to-andesitic magmas which have low viscosities and low gas contents, whereas explosive eruptions are typical of andesitic-to-rhyolitic magmas which have high viscosities and high gas contents.
When magma has a high viscosity How is it most likely to erupt?
A high viscosity magma will flow more readily and easily than a low viscosity magma. Therefore the eruption will be fluid and passive. A high viscosity magma will flow more readily and easily than a low viscosity magma. Therefore the eruption will be explosive.
At which type of plate boundary would you expect to find the most explosive volcanic activity?
Subduction Zone Volcanism Most explosive eruptions occur in volcanoes above subduction zones, where one tectonic plate dives beneath the other.
What is the process of generating magma?
As the denser tectonic plate subducts, or sinks below, or the less-dense tectonic plate, hot rock from below can intrude into the cooler plate above. This process transfers heat and creates magma. Over millions of years, the magma in this subduction zone can create a series of active volcanoes known as a volcanic arc.
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.
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.
Which magma produces the most explosive eruptions?
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.
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.
What causes explosive eruptions in volcanoes?
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.
What characteristics of magma affects the explosiveness of a volcanic eruption?
Magmas with higher silica concentration are more viscous, and thus move slower than magmas with less silica. Where tectonic plates come together, volcanoes often have thicker, viscous magma with high gas content. This combination is explosive because the gases cannot easily boil out.
What causes some volcanoes to have very explosive eruptions?
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 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 magma influences the explosiveness of an eruption?
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 characteristics of magma mainly affect the explosiveness of a volcanic eruption?
Magmas with higher silica concentration are more viscous, and thus move slower than magmas with less silica. Where tectonic plates come together, volcanoes often have thicker, viscous magma with high gas content. This combination is explosive because the gases cannot easily boil out.
What are the characteristics of magma that create explosive eruptions?
Explosive eruptions are favored by high gas content and high viscosity (andesitic to rhyolitic magmas). Explosive bursting of bubbles will fragment the magma into clots of liquid that will cool as they fall through the air.
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.
What makes a volcano more explosive?
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.
What causes more explosive eruptions?
The type of eruption a volcano has depends on the composition of the magma. Silica-rich, felsic magma can trap a lot of gas. So these magmas produce explosive eruptions.
What makes magma explosive?
As magma rises and pressure is released, gas bubbles (mainly of water vapor and carbon dioxide) form and expand rapidly, causing explosions. Magmas with high silica content tend to erupt violently, because they are viscious.
What factors make eruptions more explosive?
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.
What makes a volcanic eruption explosive?
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.
What makes volcanoes 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.
How do explosive eruptions occur?
Explosive eruptions occur where cooler, more viscous magmas (such as andesite) reach the surface. Dissolved gases cannot escape as easily, so pressure may build up until gas explosions blast rock and lava fragments into the air! Lava flows are much more thick and sticky so do not flow downhill as easily.
What causes explosive volcanic eruptions?
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.
What causes explosive eruptions?
Explosive eruptions occur where cooler, more viscous magmas (such as andesite) reach the surface. Dissolved gases cannot escape as easily, so pressure may build up until gas explosions blast rock and lava fragments into the air! Lava flows are much more thick and sticky so do not flow downhill as 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?