What causes the difference between quiet and explosive eruptions?

The difference between a quiet and explosive eruption is the silica content. In a quiet eruption, the magma is low in silica, allowing the magma to flow out gently. In an explosive eruption, the magma is high in silica, which causes the magma to be thick and sticky.

1. What makes quiet vs explosive eruptions?
2. What makes an eruption quiet?
3. What is the main hazard from a quiet volcanic eruption?
4. What factors affect the explosiveness of a volcanic eruption?
5. Why do explosive eruptions occur?
6. What is the difference between explosive eruption and effusive eruption?
7. What type of volcano produces quiet eruptions of lava flows?
8. Which type of rock would likely be formed from an explosive volcanic eruption?
9. Does a pyroclastic flow occur during a quiet eruption?
10. Why are some volcanoes more explosive than others?
11. What type of eruption is the most explosive?
12. What happens during an explosive volcanic eruption?
13. What is the meaning of explosive eruption?
14. Where do explosive eruptions occur?
15. What type of magma causes explosive eruptions?
16. When a volcano erupts quietly what kind of mountain forms?
17. Which volcano is the least explosive?

What makes quiet vs explosive eruptions?

The amount of water vapor and other gases present is one factor that determines whether a volcanic eruption will be quiet or explosive.

What makes an eruption quiet?

Magma is less dense than the surrounding rock and rises up to the surface through cracks and crevices under the Earth's surface causing an eruption of lava. ... Over time the layers of lava build up a volcanic cone. Low silica volcanoes are characterized by "quiet" eruptions.

What is the main hazard from a quiet volcanic eruption?

Hazards from quiet lava flows include igniting fires and producing chlorine-rich gas clouds where lava pours into the sea. Since 1980, as many as five volcanoes have erupted each year in the United States. Eruptions are most likely to occur in Hawaii and Alaska.

What factors affect the explosiveness of a volcanic eruption?

An eruption, explosive or otherwise, depends on three, fundamental factors: the nature of the magma, the depth of the magma chamber below the surface, and the excess pressure built up in the magma chamber (compared to what the pressure would be if an unobstructed column of magma extended to the surface).

Why do explosive eruptions occur?

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! Lava flows are much more thick and sticky so do not flow downhill as easily.

What is the difference between explosive eruption and effusive eruption?

If lava is flowing out of the volcano, we would call this an effusive eruption. On the other hand, when gas and broken fragments are shot up into the atmosphere, the magma has literally exploded before falling back to Earth. If the magma has been blown to pieces, we would call this an explosive eruption.

What type of volcano produces quiet eruptions of lava flows?

A quiet eruption of low-viscosity lava produces a wide, flat volcano called a shield volcano. If an eruption is entirely ash and cinders, the result will be a small, steep-sided volcano called a cinder cone.

Which type of rock would likely be formed from an explosive volcanic eruption?

Tuff is an igneous rock that forms from the products of an explosive volcanic eruption. In these eruptions, the volcano blasts rock, ash, magma and other materials from its vent.

Does a pyroclastic flow occur during a quiet eruption?

A pyroclastic flow typically occurs during a(n) QUIET eruption. A(n) DORMANT volcano is erupting or may erupt in the near future. Ash, cinders, and bombs build up in a steep pile to form CINDER CONE volcanoes. Lava that flows out of cracks and cools forming high layers is called a LAVA PLATEAU.

Why are some volcanoes more explosive than others?

Some volcanic eruptions are more dangerous than others, says Dr. ... 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.

What type of eruption is the most explosive?

A Plinian eruption is the most explosive of the eruption types. Mt. St. Helens eruption was a plinian eruption.

What happens during an explosive volcanic eruption?

Explosive eruptions can form pyroclastic flows that sweep down valleys, destroying everything in their path. They also send ash high into the atmosphere, forming plumes.

What is the meaning of explosive eruption?

In volcanology, an explosive eruption is a volcanic eruption of the most violent type. ... Such eruptions result when sufficient gas has dissolved under pressure within a viscous magma such that expelled lava violently froths into volcanic ash when pressure is suddenly lowered at the vent.

Where do explosive eruptions occur?

Most explosive eruptions occur in volcanoes above subduction zones, where one tectonic plate dives beneath the other. Eighty to 120 kilometers below the surface, magma forms when the rocks of the mantle melt just above the subducting plate.

What type of magma causes explosive eruptions?

Explosive eruptions are favored by high gas content & high viscosity magmas (andesitic to rhyolitic magmas).

When a volcano erupts quietly what kind of mountain forms?

A shield volcano is a gently sloping mountain. It forms when a volcano erupts quietly. Thin layers of lava build up slowly over a large area around the vent.

Which volcano is the least explosive?

Shield volcanoes tend to be the least explosive volcanoes. Most of the material they produce is lava, rather than the more explosive pyroclastic material.