What Is Viscosity And How Does It Affect Volcanic Eruptions?
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 is viscosity in volcanoes?
What is viscosity and how does it affect volcanic eruptions quizlet?
Viscosity is the resistance to the flow of a substance. Viscosity is directly related to the amount of silica content. The more viscous the magma the more explosive the volcanic eruption will happen.
What is the effect of the magma viscosity and volcanic eruption?
If the magma has high gas content and high viscosity the gas will expand in an explosive fashion and break the liquid into clots that fly through the air and cool along their path through the atmosphere. Alternatively it blast out solid pieces of rock that once formed the volcanic edifice.
What factors affect volcanic eruptions?
The style of eruption depends on a number of factors including the magma chemistry and content temperature viscosity (how runny the magma is) volume and how much water and gas is in it the presence of groundwater and the plumbing of the volcano.
Why do volcanoes have different viscosity?
Magma and a Volcanoes Shape
High-silica (basalt) magma has a much lower viscosity. It flows much easier and over longer distances. As low-silica magma cools it hardens to rock adding a new thin layer of rock to the volcano.
What is viscosity in geology?
How does the viscosity of the magma fed to volcanoes affect nearby life and property?
How does the viscosity of the magma fed to volcanoes affect nearby life and property? A volcano that expels highly viscous magma is a greater threat to life and property because it is more explosive and thus is more difficult or impossible to predict.
Which of the following affects the viscosity of a magma?
Viscosity of Magmas
Viscosity is the resistance to flow (opposite of fluidity). Viscosity depends on primarily on the composition of the magma and temperature. Higher SiO2 (silica) content magmas have higher viscosity than lower SiO2 content magmas (viscosity increases with increasing SiO2 concentration in the magma).
How does magma viscosity influence the explosive potential?
A more viscous (thick) magma will produce a more violent eruption This is controlled in part by the concentration of silica in the magma. A magma with low silica (<45%) will be runny and so the eruption will not be explosive. … A magma with low silica (<45%) will be runny and so the eruption will not be explosive.
How does viscosity affect the explosiveness of a volcano?
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 roles do gases and viscosity play in the generation of explosive eruptions?
Higher viscosity and gas content = Higher the eruption. … a large volcanic crater with a diameter of 1 km formed by the explosive volcanic eruption and collapse of surface rock into a partially emptied magma chamber. Describe how a caldera forms.
Why do volcanoes with very viscous magmas erupt the most explosively?
crystals in magma make it more viscous so magma with a high crystal content is more likely to explode than flow.
How does the viscosity of magma affects its temperature?
Viscosity of magma the resistance to flow depends on composition of the magma and temperature. Higher silica content means higher viscosity. But lower temperatures and low gas content mean higher viscosity. Hence lower viscosity and low gas content mean higher temperature of magma.
What are the three main components that affect volcanic eruptions?
What is the cause and effect of volcanic eruption?
| Positive | Negative |
|---|---|
| The high level of heat and activity inside the Earth close to a volcano can provide opportunities for generating geothermal energy. | Lava flows and lahars can destroy settlements and clear areas of woodland or agriculture. |
How do volcanic eruptions affect the shape of a volcano?
Molten rock is less dense than the surrounding rock so it is buoyant and rises just like hot air. Each eruption can produce layers of lava that will later become volcanic rock. These layers build the volcano. … This material piles up right around the volcano forming a steep cone a classic volcano shape.
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.
What type of volcano has low viscosity?
Shield volcanoes
Shield volcanoes Where a volcano produces low viscosity runny lava it spreads far from the source and forms a volcano with gentle slopes: a shield volcano. Most shield volcanoes are formed from fluid basaltic lava flows. Mauna Kea and Mauna Loa are shield volcanoes.
What is viscosity in science?
Viscosity is the resistance of a fluid (liquid or gas) to a change in shape or movement of neighbouring portions relative to one another. Viscosity denotes opposition to flow.
What type of volcano has lava with high viscosity?
Intermediate lavas are more viscous than the mafic lava which forms shield volcanoes (see above) and normally contain more volatiles.
Do composite volcanoes have high or low viscosity?
What magma composition and viscosity is associated with shield volcanoes?
Why does a volcano fed by highly viscous magma pose the greatest threat to life and property?
A volcano fed by highly viscous magma is likely to be a greater threat to life and property than a volcano supplied with very fluid magma because with high viscous magma gas is trapped more in the magma so the gas will build up and then eventually explode whereas with fluid magma the gas can escape allowing the magma …
How does the composition and viscosity of lava flows differ between composite volcanoes and shield volcanoes?
How does the composition and viscosity of lava flows differ between composite volcanoes and shield volcanoes? Composite volcanoes tend to have intermediate to felsic lava that is very viscous whereas shield volcanoes have basaltic lava that is low in viscosity.
Which eruption has lower viscosity magma?
form pillow basalts. basalt lava flows. the low viscosity of basaltic magma allows it to flow downhill for long distances.
What are the volcanic eruptions?
What does the viscosity of magma determine?
The higher the amount of silica in the magma the higher is its viscosity. Viscosity is a liquid’s resistance to flow. Viscosity determines what the magma will do. … Dissolved gases become trapped by thick magma and the magma chamber begins to build pressure.
How does silica content affect volcanic eruptions?
What type of eruption is the most explosive?
Which type of volcanic eruption is very explosive?
Why does low viscosity lava produce gentle eruptions?
If a magma has low viscosity (it is runny) gas can escape easily so when the magma erupts at the surface it forms lava flows. These eruptions are (relatively!) gentle effusive eruptions.
Which type of volcano is the most violent and explosive?
Stratovolcanoes are considered the most violent. Mount St. Helens in Washington state is a stratovolcano that erupted on May 18 1980.
What are the three factors that affect the viscosity of magma?
The three factors that influence the viscosity of a lava are temperature the dissolved gases it contains and its chemical composition.
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