Is high in silica content and viscosity?
Magmas with high silica content have a high viscosity (resistance to flow) and are generally more explosive when eruptions occur. All magmas also contain some degree of trapped gasses (CO2 & H2O ). The more trapped gas the more violent the explosion. All magma that reaches the surface can be classified as Lava.
Why does silica content increase the viscosity?
The cooler the lava, the higher the viscosity (the thicker it is). Composition: he more felsic the lava (the more silica in the lava), the higher the viscosity because silica forms chains in the cooling lava even before it crystallizes. The more mafic the lava (the less silica in it), the lower the viscosity.
Does high silica content make viscosity high or low?
Volcanic Eruptions: High Silica 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.
What is the relationship between silica and the viscosity of the magma?
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. Mafic magma is not viscous and will flow easily to the surface.
What is magma with low silica content?
The silica content and the amount of gas in the lava determines how fluid the lava is and how easily it will flow. High silica content produces a thick viscous lava that does not flow easily. Low silica content produces a lava that is more fluid and flows more easily.
Which mineral has the highest viscosity?
The magma that has the highest viscosity is rhyolitic magma.
How does temperature and silica content affect the viscosity of magma?
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 3 factors affecting 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.
What does magma with high silica content form?
High silica content produces a thick viscous lava that does not flow easily. Low silica content produces a lava that is more fluid and flows more easily. Lava is less dense than the surrounding rock and rises up to the surface through cracks and crevices under the Earth.
Is the viscosity of magma that is high in silica higher or lower than magma that is low in silica?
Magmas that have a high silica content will therefore exhibit greater degrees of polymerization, and have higher viscosities, than those with low-silica contents. The amount of dissolved gases in the magma can also affect it's viscosity, but in a more ambiguous way than temperature and silica content.
What affects the viscosity of magma?
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.
Why is silica content so important?
It is the silica content that controls the viscosity of the magma, and hence the nature of the volcanism that is seen. The low levels of silica mean that Hawaiian magma has a low viscosity, which explains why we see lava readily cascading downslope, and being churned up in the air in great fire fountains.
Which has higher viscosity?
Viscosity is a measure of how much a Substance resists flowing freely. Solids have high viscosity because they cannot flow freely. Viscosity of liquids ranges from low to high whereas gases have a low viscosity. Hence, wood being a solid has a very high viscosity.
What happens when viscosity increases?
A general increase in viscosity at higher temperatures, which results in lower oil consumption and less wear. A reduced viscosity at lower temperatures, which will improve starting and lower fuel consumption.
Why does silica make magma more viscous?
Silicon dioxide, the most abundant rock-forming compound on Earth and the predominant molecular constituent of volcanic rocks and magmas. It tends to polymerize into molecular chains, increasing the viscosity of the magma.
What increases the viscosity of magma?
Viscosity is anti-correlated to temperature by the fact that a lower temperature means a higher viscosity. In other words, as magma cools, its viscosity increases.
What is a silica content?
The silica content determines how thick the lava is, how easily it flows and how easily dissolved gases can escape; therefore the silica content determines the characteristic of the volcanic eruption and the resulting volcanic cone.
Why does silica affect lava flow?
Silica: Influences lava viscosity and overall shape of the volcano. Silica molecules form a strong bond that permits entrapment of volcanic gases and promotes explosive volcanic eruptions. Low-silican magmas allow rapid escape of gases and low-explosivity eruptions.
What are the factors affecting the viscosity of magma?
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.
What increases viscosity of magma?
Viscosity is anti-correlated to temperature by the fact that a lower temperature means a higher viscosity. In other words, as magma cools, its viscosity increases.
What does viscosity depend on?
The viscosity of a liquid usually depends on its temperature. Viscosity generally decreases as the temperature increases. Viscosity generally increases as the temperature decreases. The viscosity of a liquid is related to the ease with which the molecules can move with respect to one another.
What factors affect viscosity?
CONCEPT: Viscosity: The state of being sticky, thick, and semi-fluid inconsistency, due to internal friction of fluids is called viscosity. The viscosity of a material is affected by temperature, pressure, nature of fluid, velocity gradient , etc.
What are 3 factors that affect viscosity?
Those are:
- Fluid Temperature: Usually the viscosity of liquids decreases with an increase in temperature. …
- Flow Conditions: For laminar flow the viscosity of liquid remains constant while for turbulent flow viscosity changes.
- Pressure: With an increase in pressure, the viscosity of gases usually increase.
What causes viscosity to decrease?
Viscosity generally decreases as the temperature increases. Viscosity generally increases as the temperature decreases. The viscosity of a liquid is related to the ease with which the molecules can move with respect to one another.
Why silica content affects the characteristics of magma?
Magmas that have a high silica content will therefore exhibit greater degrees of polymerization and have higher viscosities than those with low-silica contents. The amount of dissolved gases in the magma can also affect it's viscosity but in a more ambiguous way than temperature and silica content.
What makes magma less viscous?
Lower temperature magmas have higher viscosity than higher temperature magmas (viscosity decreases with increasing temperature of the magma).
What is the function of silica?
Silica has widespread industrial applications including use as a food additive, i.e., anti-caking agent, as a means to clarify beverages, control viscosity, as an anti-foaming agent, dough modifier, and as an excipient in drugs and vitamins.
Which has the most silica content?
Quartz; Quartz is the most abundant silica mineral. Pure Quartz is colorless and transparent. It occurs in most igneous and practically all metamorphic and sedimentary rocks. It is used as a component of numerous industrial materials.
Why does silica content have such an important function in the viscosity of lava?
Silica: Influences lava viscosity and overall shape of the volcano. Silica molecules form a strong bond that permits entrapment of volcanic gases and promotes explosive volcanic eruptions. Low-silican magmas allow rapid escape of gases and low-explosivity eruptions.
What causes high viscosity?
Hyperviscosity can be caused by your blood cells changing shape or by an increase in serum proteins, red blood cells, white blood cells, or platelets. The reduced blood flow caused by hyperviscosity syndrome is a dangerous phenomenon and can have far-reaching effects on the whole body.