0
The silicate compounds are more viscous and hold gases and water under pressure, and the gases and steam expand violently once the lava reaches the surface. Less silica means that some of these gases will bubble out before reaching critical pressure.
What else can I help you with?
What effect does silica content have on the magma?
Silica content makes the magma thicker which can cause a more explosive eruption, and also make it so more gases aer open to be trapped
Why is silica rich magma associated with explosive eruptions?
Silica-rich magma has high viscosity, which can trap gas bubbles. When pressure builds up, the gas can cause explosive eruptions as it tries to escape through the thick magma. The high silica content also promotes the formation of explosive pyroclastic materials during an eruption.
Do silica-rich magma cause explosive eruptions?
yes
Does low silica magma cause explosive volcanic eruptions?
Not usually. Explosive eruptions are more often to magma with high or moderate silica levels.
What happen if there is a lot of water present in the magma?
Magma with high water content is more likely to cause an explosive eruption because magma is underground, which means it's under intense pressure, and the water stays dissolved in the magma. When magma quickly rises to the surface, the pressure decreases and other compounds, such as Carbon Dioxide (CO), become gases. As gases expand rapidly an explosion can happen.
What makes a quiet eruption different from an explosive eruption?
quiet eruption flows easeir cause it has a low viscosity and lava flows easier but explosive eruption has a high viscosity and lava flows slower
What are two reasons that magma with a high silica content tend to cause explosive eruptions?
Magma with a high silica content tend to cause explosive eruptions because it has a stiff consistency and blocks the vents. When magma pushes from behind it more pressure happens which means the eruption will be explosive. It also prevents gas and water vapor from getting out. The gases will expand until it explodes.
Why is silica rich magma explosive?
This is because silica-rich magma is thicker. The thicker the magma, the chance for the dissolved gas in there to escape is less likely. This causes an explosion. When the gases do escape, they cause an even bigger explosion
Why do volcanic eruptions differ?
The main cause of differences in volcanic eruption characteristics is due to the viscosity of the magma. High viscosity magmas are high in sticky silica which traps gas and produces explosive eruptions. Low viscosity magmas are low in silica and produce eruptions with far less energetic characteristics.
What type of magma that tends to cause explosive eruptions has a what?
Magma that tends to cause explosive eruptions is typically high in silica content, making it thick and viscous. This results in gas build-up and pressure within the magma chamber, leading to explosive eruptions.
Why is magma with less silica less likely to cause explosive eruptions?
The silicate compounds are more viscous and hold gases and water under pressure, and the gases and steam expand violently once the lava reaches the surface. Less silica means that some of these gases will bubble out before reaching critical pressure.
What type of lava flow was mount st Helens?
Dacite, a volcanic rock with about 65% silica. This amount of silica in dacite is a lot higher than the basalts of Hawaii which have less than 50% silica. The high silica content makes the magma "sticky" and can cause more pressure to build up. With so much pressure, eruptions from Mount St. Helens can be very violent like the famous 1980 eruption.
