How magma behaves when it gets gassed up Geologist Ben Andrews taking video on the volcano Santa MarĂ­a in Guatemala. (Smithsonian photo/gnuckx, public domain)
How magma behaves when it gets gassed up
Lexile

Lava is the most famous hazard of volcanoes. It is featured in movies. It used to describe lamps, chocolate cakes and mobile phone cases. But lava is only part of the volcano story. Lava is what we call magma when it flows out of a volcano. Magma is molten - or melted - rock. You would not want to stand in lava. It can be as hot as 2,000 Fahrenheit. At a walking pace you could outrun the majority of lava flows. So, what’s so hazardous about a volcanic eruption?

Sometimes magma does not flow out of a volcano. Instead, it explodes. When that exploding mixture of hot gas, magma, and rock comes out, it is fast and unpredictable. 

In an explosive eruption, pieces of hardening magma and rock are spewed upward. They form a hot plume of gas. They range from the tiny particles that make up volcanic ash to chunks the size of cars. As the plume blows downwind, it drops materials like a hail storm. It litters the landscape with volcanic rocks. A pyroclastic flow of hot gases carrying the heavier material may pick up speed as it sweeps down from the volcano. As the flow mixes with the surrounding air, lighter ash may get lofted up in a cloud. It can travel as far as thousands of miles. 

The bigger chunks are an immediate hazard to people and wildlife around the volcano. But the cloud of ash takes a long-term toll that can be devastating. The 1980 eruption of Mount St. Helens in Washington state produced a pyroclastic flow that scoured the landscape at speeds up to 600 miles per hour. It lofted ash that settled on 11 states over the next few days. 

The 2010 eruption of Iceland’s Eyjafjallajökull volcano sparked electrical storms. It had an ash plume more than 5 miles high, spreading over Europe and grounding airline travel for days. 

Geologists who study volcanoes - volcanologists - are trying to better understand the behavior of these pyroclastic currents. Given the danger of capturing data directly from an explosive eruption, volcanologists such as Smithsonian’s Dr. Ben Andrews have found ways to capture data from a distance and simulate flows in laboratories. Ben’s Eruption Simulator uses laser beams and talcum powder to observe how erupted materials get distributed upward and outward in different scenarios.  

Learn more about Ben’s volcano research in the "Smithsonian Science How" webcast on Thursday, Dec. 14, 2017. Watch How Volcanic Eruptions Send Materials Up and Out, airing at 11 a.m. and 2 p.m. EST on the Q?rius website. Ben will take you on an explosive journey while answering your questions live. You can also get teaching resources to use with the webcast.

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CRITICAL THINKING QUESTION
What is magma?
Write your answers in the comments section below


COMMENTS (47)
  • GemmaV-del
    11/28/2017 - 04:05 p.m.

    hot fluid or semifluid material below or within the earth's crust from which lava and other igneous rock is formed by cooling.

  • AngelinaB-del
    11/28/2017 - 04:09 p.m.

    This article is about how magma behaves when it gets gassed up. Lava is the most famous danger of volcanoes. However, lava is only part of the "volcanic story". Lava is also called magma when it flows out of a volcano. Magma is molten or melted rock. Sometimes, magma does not flow out of a volcano, it explodes. When that happens, it becomes a mixture of hot gas, magma, and rock which is usually fast and unpredictable. In this explosive eruption, pieces of hardening magma and rock are "spewed" upward which forms a hot plume of gas. They can range from tiny particles to chunks the size of cars. These big chunks are hazardous to people and wildlife around the volcano. Geologists who study volcanoes, volcanologists, are trying to better understand the behavior of these "pyroclastic" currents.

  • JadeR-del
    11/28/2017 - 04:23 p.m.

    SUMMARY- This article is about how when magma gets gassed up its behavior changes. The text says "Sometimes magma does not flow out of a volcano. Instead, it explodes. When that exploding mixture of hot gas, magma, and rock comes out, it is fast and unpredictable." Therefore magmas behavior changes when gassed up.

  • TiffanyW-del
    11/28/2017 - 04:39 p.m.

    Lava is what we call magma when it flows out of a volcano. Sometimes magma does not flow out of a volcano. Instead, it explodes. When that exploding mixture of hot gas, magma, and rock comes out, it is fast and unpredictable. In an explosive eruption, pieces of hardening magma and rock are spewed upward. They form a hot plume of gas.

  • JaidenV-del
    11/28/2017 - 04:42 p.m.

    The magma changed due to the fact of mixture it can sonrientes flow out or explode Geologists are trying to study it more on the heavier of the pyrocladtic currents.

  • IsabellaM-del
    11/28/2017 - 04:53 p.m.

    This article is about how magma reacts to gas. I thought this article was interesting to read about.

  • JosephF-del
    11/28/2017 - 04:56 p.m.

    Magma is a hot rock solution that is deep in the earth and once it reaches the surface of the earth, it forms rocks.

  • PriscillaD-del
    11/28/2017 - 04:58 p.m.

    This article is about the danger of magma when it is gassed up. But it is also about the very hot heat of magma, and how it could be extremely dangerous to be near a volcano when magma explodes from it. Especially when magma is gassed up, it can be incredibly dangerous and hazardous to any people or wildlife around it.

  • SaraM-del
    11/28/2017 - 05:00 p.m.

    This article speaks about magma.Lava had came out of St. Helen. I thought this was boring.

  • NatalieH-del
    11/28/2017 - 05:13 p.m.

    Magma turns into huge chunks when it gets gassed. The chunks could be really tiny to really huge. The bigger the chunks are, the more dangerous they could be.

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