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 is the most explosive type of volcanic activity associated with?
Plinian eruptions are the most destructive type of eruption. They release a deadly mixture of lava, ash, and volcanic rocks such as scoria and pumice, which can fall kilometers away from the eruption site.
How does magma viscosity influence the explosive potential?
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.
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.
What makes some volcanoes more explosive than others?
Magma that has erupted is called lava. Some volcanic eruptions are explosive and others are not. The explosivity of an eruption depends on the composition of the magma. If magma is thin and runny, gases can escape easily from it.
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 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.
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 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?
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 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.
What makes volcanoes 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.
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).
Why do explosive volcanoes 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.
Which volcanoes produce explosive eruptions?
Hawaiian volcanoes have produced explosive eruptions ranging in size and vigor from relatively small lava fountains to large eruptions.
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 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.
What volcanoes have explosive eruptions?
Hawaiian volcanoes have produced explosive eruptions ranging in size and vigor from relatively small lava fountains to large eruptions.
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.
What is the most explosive type of magma?
Pelean eruptions are considered violently explosive. Plinian – These eruptions result from a sustained ejection of andesitic to rhyolitic magma into eruption columns that may extend up to 45 km above the vent.
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.
What type of magma is explosive?
Explosive eruptions are favored by high gas content and high viscosity (andesitic to rhyolitic magmas).
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 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 features of a magma would likely make a volcano more explosive?
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 of the following can cause more explosive volcanic 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.
Which property of magma is important for determining how explosive an eruption will be?
CONTROLS ON EXPLOSIVITY The viscosity of the magma, however, is also an important factor in determining whether an eruption will be explosive or nonexplosive. A low-viscosity magma, like basalt, will allow the escaping gases to migrate rapidly through the magma and escape to the surface.
What characteristics of magma mainly affect the explosiveness of a volcanic eruption?
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.