What volcanoes are made from low viscosity magma?

What volcanoes are made from low viscosity magma?

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 type of volcanoes erupts with low viscosity?

Shield volcanoes are built by many layers over time and the layers are usually of very similar composition. The low viscosity also means that shield eruptions are non-explosive. Eruptions tend to be mild in comparison to other volcanoes, but lava flows can destroy property and vegetation.

Do volcanoes with low viscosity erupt violently?

Non explosive eruptions are favored by low gas content and low viscosity magmas (basaltic to andesitic magmas). If the viscosity is low, non-explosive eruptions usually begin with fire fountains due to release of dissolved gases.

How does magma viscosity affect the shape of volcanoes?

The viscosity (thickness) of the magma that erupts from a volcano affects the shape of the volcano. Volcanoes with steep slopes tend to form from very viscous magma, while flatter volcanoes form from magma that flows easily.

How does viscosity affect how a volcano erupts?

Viscosity is the ability of a liquid to resist flowing. This means liquids with a higher viscosity are thicker and do not flow as easily. Magmas with a higher SiO2 content have a higher viscosity. Ultimately, the viscosity of a magma will determine the shape a volcano takes over continued eruptions.

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. The viscosity and gas content of a magma determines how it erupts.

How does magma temperature affect viscosity?

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. A higher concentration in silica leads to a more acid/more viscous 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.

What is in magma that causes some volcanoes to explode?

The standard explanation for explosive volcanism is that as liquid magma rises from a magma chamber at a depth of several miles, dissolved gases – mostly water – form bubbles. As bubbles grow, the overall magma volume increases, causing it to rise even faster.

What does low viscosity lava mean?

When lava has low viscosity, it can flow very easily over long distances. But most importantly, highly viscous lava is associated with explosive eruptions and dangerous pyroclastic flows. An example of a low viscosity (fast flowing) lava is basaltic lava.

Does low viscosity lava have low silica content?

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 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 is the difference between magma and lava?

Magma and Lava have different meanings. Magma is a molten and liquid rock that is only found below the earth’s surface. That is because once it reaches the surface it becomes lava. This substance is made up of a combination of dissolved gases, rock fragments and crystals and the liquid part of it is referred to as the melt.

What factors affect the viscosity of magma?

Starting with chemical composition, the key factor affecting viscosity is the amount of silica (which is found as SiO2) in the magma. Basalts, often referred to as basic or mafic rocks, have a relatively low percentage of SiO2. Basaltic magma comes from the upper regions in the mantle and erupts in relatively primitive, or unaltered, condition.

What is the science of a volcano?

The Science Behind Volcanoes. A volcano is an opening, or rupture, in a planet’s surface or crust, which allows hot magma, volcanic ash and gases to escape from the magma chamber below the surface.

What determines the explosivity of a volcano?

A volcano’s explosivity is linked to the composition of its magma. The magma composition, in turn, is dependent on the volcano’s tectonic setting: mid-oceanic ridge volcanoes erupt basaltic magma, while more silicic magmas are erupted along subduction zones.