Why is a volcano that has thick magma likely to be a greater threat than a volcano that has very fluid magma?
Why is a volcano fed by highly viscous magma likely to be a greater threat than a volcano supplied with very fluid magma? The more fluid magma is typically hotter and has a lower volatile content than the more viscous magma.
What happens when the magma is more viscous?
If the liquid part of the magma has a high viscosity, then the gas will not be able to expand very easily, and thus, pressure will build up inside of the gas bubble(s).
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.
How does magma viscosity affect volcanoes?
Ultimately, the viscosity of a magma will determine the shape a volcano takes over continued eruptions. A magma's silica content will not only control the rock type that forms, it also controls the relative viscosity of the magma. Differences in a magma's viscosity will determine the shape a volcano takes.
Why is a volcano that is fed by highly viscous magma likely to be a greater threat to life and property than a volcano supplied with a very fluid magma?
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 viscosity of a lava affect the steepness of a volcano slope?
The low viscosity of the magma allows the lava to travel down slope on a gentle slope, but as it cools and its viscosity increases, its thickness builds up on the lower slopes giving a somewhat steeper lower slope. Most shield volcanoes have a roughly circular or oval shape in map view.
Why do volcanoes with viscous lava have more explosive eruptions?
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.
Why does a high gas content in a high viscosity magma result in an explosive eruption?
The high pressure keeps the gas in solution in the liquid, but when pressure is decreased, like when you open the can or bottle, the gas comes out of solution and forms a separate gas phase that you see as bubbles. Gas gives magmas their explosive character, because volume of gas expands as pressure is reduced.
What would magma with the highest viscosity contain?
Answer and Explanation: 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… See full answer below.
Why is viscous lava more explosive?
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 does viscosity mean in volcanoes?
When it comes to liquids, viscosity is a measurement of how thick or syrupy it is. Water has low viscosity, while corn syrup, for example, is highly viscous. You can measure lava in terms of viscosity as well. And the lava viscosity defines the size and shape of a volcano.
Which of the three types of volcanoes discussed pose the greatest threat to property and human life?
pyroclastic flows and lahars are most dangerous to human life. Ash fall and lava flows affect property.
Which statement describes the composition and viscosity of the lava associated with shield volcanoes?
Which statement describes the composition and viscosity of the lava associated with shield volcanoes? Lava from shield volcanoes is mafic and has a low viscosity.
What is viscous magma?
MAGMA VISCOSITY. The character of volcanic eruptions are largely controlled by the viscosity – “gooeyness” or resistance to flow – of the magma: Low viscosity fluids flow more easily than high viscosity fluids.
What effect does viscosity have on how explosive a volcanic eruption is?
Overall, viscosity in a volcano's magma determines the amount of force required to fragment or break through magma. The more viscous a volcano's magma, the better conditions are for a violent eruption. The time allowed for degassing also ties into the violent nature of many eruptions.
What type of volcanic eruption happen when the magma is thicker and more vicious that made the gases difficult to escape?
Explosive eruptions Explosive eruptions generally involve magma that is more viscous and has a higher gas content. Such magma is often shattered into pyroclastic fragments by explosive gas expansion during an eruption. Volcanic eruptions may fall into six major types: Icelandic, Hawaiian, Strombolian, Vulcanian, Pelean, and Plinian.
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 lava is the most viscous?
The magma that has the highest viscosity is rhyolitic magma.
What volcano has lava type is highly viscous?
Stratovolcano. Stratovolcanoes have relatively steep sides and are more cone-shaped than shield volcanoes. They are formed from viscous, sticky lava that does not flow easily.
Why does more viscous magma produce more explosive volcanoes?
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 the biggest threat during a volcanic eruption?
Volcanoes spew hot, dangerous gases, ash, lava, and rock that are powerfully destructive. People have died from volcanic blasts. Volcanic eruptions can result in additional threats to health, such as floods, mudslides, power outages, drinking water contamination, and wildfires.
Which volcanic hazard poses the greatest threat to human?
pyroclastic flows and lahars are most dangerous to human life. Ash fall and lava flows affect property.
How does the composition and viscosity of lava flows differ between composite volcanoes and shield volcanoes quizlet?
How does the composition and viscosity of lava flows differ between composite volcanoes and shield volcanoes? Composite volcanoes are mostly formed from thick, viscous, andesitic composition lava whereas shield volcanoes are formed from runny, less viscous, basaltic composition lava.
What could be the reasons for these volcanoes to have high eruptive force?
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 the most viscous magma?
Stratovolcano. Stratovolcanoes have relatively steep sides and are more cone-shaped than shield volcanoes. They are formed from viscous, sticky lava that does not flow easily.
Which magma type erupts most violently?
A Plinian eruption is the most explosive of the eruption types.
Which type of magma typically results in the greatest explosive events?
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 magma viscosity influence the explosive potential quizlet?
How do each of these factors affect the explosiveness of an eruption? 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.
Why some volcanic eruptions are violent and 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 lava more viscous?
Temperature: The hotter the lava, the lower the viscosity (the thinner it is). 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.