Mount St. Helens’ magma is inherently more explosive than the Kīlauea magma: it has more water in it than Kīlauea magma, and is delivered to the surface at a higher pressure because of higher magma viscosity. So Mount St. Helens tends to have explosive eruptions and Kīlaueaa eruptions are generally non-explosive.
What causes a volcano to erupt violently?
A volcano’s explosiveness depends on the composition of the magma (molten rock) and how readily gas can escape from it. As magma rises and pressure is released, gas bubbles (mainly of water vapor and carbon dioxide) form and expand rapidly, causing explosions.
What two main factors result in more violent eruptions?
Explosive eruptions are favored by high gas content & high viscosity magmas (andesitic to rhyolitic magmas). The explosive bursting of bubbles fragments the magma into clots of liquid that cool as they fall through the air. These solid particles become pyroclasts or volcanic ash.
Which type of volcano is the most violent and explosive?
Stratovolcanoes
Stratovolcanoes are more likely to produce explosive eruptions due to gas building up in the viscous magma. Andesite (named after the Andes Mountains), is perhaps the most common rock type of stratovolcanoes, but stratovolcanoes also erupt a wide range of different rocks in different tectonic settings.
Which volcano is the least explosive?
Shield volcanoes
Answer and Explanation: Shield volcanoes tend to be the least explosive volcanoes. Most of the material they produce is lava, rather than the more explosive pyroclastic material.
What was the most violent eruption in history?
The most violent eruption registered in history was that in the La Garita Caldera in the United States. It occurred 2.1 million years ago and formed a 35 x 75 km crater, drastically changing the climate on Earth.
How do volcanoes positively affect people?
Volcanic materials ultimately break down and weather to form some of the most fertile soils on Earth, cultivation of which has produced abundant food and fostered civilizations. The internal heat associated with young volcanic systems has been harnessed to produce geothermal energy.
Which of the following are warning signs that a volcano will soon erupt?
How can we tell when a volcano will erupt?
- An increase in the frequency and intensity of felt earthquakes.
- Noticeable steaming or fumarolic activity and new or enlarged areas of hot ground.
- Subtle swelling of the ground surface.
- Small changes in heat flow.
- Changes in the composition or relative abundances of fumarolic gases.
What country has the smallest volcano?
The Cuexcomate is known as “the smallest volcano in the world” and it is located just 15 minutes away from downtown Puebla in central Mexico.
What type of volcano is Yellowstone?
supervolcano
Yellowstone National Park is situated over a supervolcano that is capable of an eruption of magnitude 8. It has had three massive eruptions, all of which created calderas.
What is lava made of?
Lava is made up of crystals, volcanic glass, and bubbles (volcanic gases). As magma gets closer to the surface and cools, it begins to crystallize minerals like olivine and form bubbles of volcanic gases. When lava erupts it is made up of a slush of crystals, liquid, and bubbles.
What is world’s worst volcano?
Deadliest Eruption
| Deaths | Volcano | When |
|---|---|---|
| 92,000 | Tambora, Indonesia | 1815 |
| 36,417 | Krakatau, Indonesia | 1883 |
| 29,025 | Mt. Pelee, Martinique | 1902 |
| 25,000 | Ruiz, Colombia | 1985 |
What volcano is the gentlest?
Hawaii volcanoes characterize the gentle type, known as shield volcanoes. Shield volcanoes occur far from the crushing compressive edges of tectonic plates. They are common in Hawaii and other Pacific Ocean island chains, and in Iceland, the Canary Islands and the East African rift, to name the most prevalent.
Why are Hawaiian volcanoes not explosive?
With infrequent exceptions, eruptions of Hawaiian volcanoes are weakly explosive or nonexplosive and relatively benign. Hawaiian eruptions are typically gentle because their lava is highly fluid and thus tends to flow freely both beneath the surface and upon eruption.
What is the largest supervolcano on Earth?
Taupo erupted 22,600 years ago and is the most recent supereruption on Earth (with a volume of about 1,130 cubic kilometers). Additional volcanoes capable of producing supereruptions include the large caldera volcanoes of Japan, Indonesia, and South America.
Is Mount Everest a volcano?
No, Mount Everest is not a volcano. It was produced from a tectonic collision between the Indian and Eurasian tectonic plates tens of millions of years ago.
What will happen if Yellowstone erupts?
If another large, caldera-forming eruption were to occur at Yellowstone, its effects would be worldwide. Such a giant eruption would have regional effects such as falling ash and short-term (years to decades) changes to global climate.
Why is it good to live near a volcano?
Farming. Volcanic environments can be good locations for farming. Volcanic deposits are enriched in elements such as magnesium and potassium. When volcanic rock and ash weathers, these elements are released, producing extremely fertile soils.
Why do people still live near volcanoes?
For starters, many people depend on volcanoes for their survival. The geothermal energy of a volcano can power technological systems for nearby communities. Soil near active volcanoes is often rich in mineral deposits and provides excellent farming opportunities.
Can humans cause volcanoes to erupt?
A warming planet due to human-induced climate change is likely to contribute to an increase in volcanic activity, according to a recent study in the journal Geology.
Is there any way to stop a lava flow why not?
There’s no way to stop lava. Once fissures open and the hot stuff starts flowing, it’s best not to fight nature. “The flows cannot be stopped, but people have tried in the past,” said Benjamin Andrews, director of the Global Volcanism Program at the Smithsonian National Museum of Natural History.