What is viscosity of mafic?
What is viscosity of mafic?
So, mafic lavas are hot , low in silica and volatiles, and have relatively low viscosity. They flow easily outward from the vent (where it comes out of the ground), and may travel great distances before completely solidifying. Felsic lavas are not as hot, high in silica and volatiles, and have a high viscosity.
What is the viscosity of mafic magma?
CONTROLS ON EXPLOSIVITY
| SiO2 | MAGMA TYPE | VISCOSITY |
|---|---|---|
| ~50% | mafic | low |
| ~60% | intermediate | intermediate |
| ~70% | felsic | high |
What are 3 types of magma and what is their viscosity?
The high temperatures and pressure under Earth’s crust keep magma in its fluid state. There are three basic types of magma: basaltic, andesitic, and rhyolitic, each of which has a different mineral composition.
What type of magma is most viscous?
Rhyolitic magmas
Rhyolitic magmas tend to have even higher viscosity, ranging between 1 million and 100 million times more viscous than water. (Note that solids, even though they appear solid have a viscosity, but it very high, measured as trillions times the viscosity of water).
What is viscosity in volcanoes?
Magmas that are more rhyolitic have a higher gas content. This gas content and relative viscosity leads to the more explosive and violent eruptions that occur at composite volcanoes. In general, SiO2 content controls the relative viscosity of a magma. Viscosity is the ability of a liquid to resist flowing.
What are three types of eruptions?
Types of eruptions
- Hydrothermal eruption. An eruption driven by the heat in a hydrothermal systems.
- Phreatic eruption. An eruption driven by the heat from magma interacting with water.
- Phreatomagmatic eruption.
- Lava.
- Strombolian and Hawaiian eruptions.
- Vulcanian eruptions.
- Subplinian and Plinian eruptions.
What is viscosity of 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).
Which type of volcano has the highest viscosity?
Lavas and pyroclastics are usually andesitic to rhyolitic in composition. Due to the higher viscosity of magmas erupted from these volcanoes, they are usually more explosive than shield volcanoes. Stratovolcanoes sometimes have a crater at the summit that is formed by explosive ejection of material from a central vent.
What are the factors affects magmas viscosity?
What type of volcano has high viscosity?
Classic examples of shield volcanoes are Mauna Kea and Mauna Loa in Hawaii, as well as Olympus Mons on Mars. When lava has a high viscosity, it’s very thick and doesn’t flow very well at all. Instead of rivers of lava, you can get crumbling piles of rock flowing down hill.