Which type of magma is known for the most violent eruptions?
Explosive eruptions are favored by high gas content and high viscosity (andesitic to rhyolitic magmas).
What causes violent volcanic eruptions?
As magma rises and pressure is released, gas bubbles (mainly of water vapor and carbon dioxide) form and expand rapidly, causing explosions. Magmas with high silica content tend to erupt violently, because they are viscious.
What component of magma causes violent volcanic eruptions?
dissolved gasCONTROLS ON EXPLOSIVITY The amount of dissolved gas in the magma provides the driving force for explosive eruptions. The viscosity of the magma, however, is also an important factor in determining whether an eruption will be explosive or nonexplosive.
What magma has explosive eruptions?
Explosive eruptions occur where cooler, more viscous magmas (such as andesite) reach the surface. Dissolved gases cannot escape as easily, so pressure may build up until gas explosions blast rock and lava fragments into the air!
What two main factors result in more violent eruptions?
The two main factors that influence how a volcano will erupt are viscosity and gas content. Both are related to the composition of the magma.
What determines the violence of a volcano?
Answer and Explanation: There are three main factors that influence the violence of a volcanic eruption: magma viscosity, magma temperature, and the number of dissolved gases.
Is felsic magma explosive?
Felsic lavas are not as hot, high in silica and volatiles, and have a high viscosity. They are thick and gooey and resist flowing. Their high volatile content makes them potentially highly explosive.
What is the most violent type of eruption?
A Plinian eruption is the most explosive of the eruption types. Mt. St. Helens eruption was a plinian eruption.
Does felsic magmas erupt explosively?
Felsic magmas erupt explosively, creating pyroclastic eruptions. Pyroclastic eruption types include tephra, ash, and lahars. Mt. Mazama blew its top off and then collapsed, creating Crater Lake in Oregon.
Which type of volcanic eruption is the least violent?
Strombolian eruptionsStrombolian eruptions are often associated with small lava lakes, which can build up in the conduits of volcanoes. They are one of the least violent of the explosive eruptions, although they can still be very dangerous if bombs or lava flows reach inhabited areas.
Are all volcanic eruptions are violent?
Some volcanic eruptions are explosive and others are not. The explosivity of an eruption depends on the composition of the magma. If magma is thin and runny, gases can escape easily from it. When this type of magma erupts, it flows out of the volcano.
What is the style of eruption for each type of volcanic eruption?
There are two types of eruptions in terms of activity, explosive eruptions and effusive eruptions. Explosive eruptions are characterized by gas-driven explosions that propels magma and tephra. Effusive eruptions, meanwhile, are characterized by the outpouring of lava without significant explosive eruption.
What are the main causes of volcanoes?
How Do Volcanoes Erupt? It is so hot deep within the earth that some rocks slowly melt and turn into a thick flowing matter known as magma. Since it is lighter than solid rock, the magma rises and collects in magma chambers. Eventually, some magma pushes through fissures and vents on the earth's surface.
Why do you think some eruptions are more violent than others?
Molten rock, or magma, comes under pressure, but it's how that pressure is released that determines whether the volcano will create a violent, sudden eruption or not, she says. "If the magma is very sticky, very viscus, it will explode.
Why are some volcanic eruptions gentle and others violent?
Volcanic eruptions can be explosive, sending ash, gas and lava high up into the atmosphere, or the magma can form lava flows, known as effusive eruptions. Whether an eruption is explosive or effusive largely depends upon the amount of gas in the magma.
What is volcanic eruption and its causes and effects?
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.