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At its simplest, lava is molten silicate rock.
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But add a little spice ...
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Seasoning lava with things like ice,
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water, crystals, and metal
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can lead to explosive results.
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Here's how lava reacts to four different factors.
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Ice and lava might feel like an odd couple,
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but frozen volcanoes are a real hazard
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in places like Iceland.
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And it's important to study this interaction
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for evacuations, especially because lava
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can move faster and farther on ice.
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Ash from the volcano can settle on the ice,
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creating an insulating barrier,
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slowing the lava's cooling.
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The ice can also melt, which can reduce friction,
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and the steam can give the lava this bubbly look.
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The more the ice melts, the higher the risk of flooding.
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Jökulhlaups are floods that happen
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when a glacial lake overfills.
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In 2010, Iceland's Eyjafjallajökull volcano
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caused a glacial outburst flood
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that forced 800 people to evacuate.
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In the same vein, glacial melt and debris
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are a perfect recipe for lahars.
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These volcanic mudflows sweep away homes,
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infrastructure, and even people without enough preparation.
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Like the 1985 eruption of Nevado del Ruiz in Colombia,
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which led to 20,000 fatalities.
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Lava has some pretty unique reactions to seawater,
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as you can see in this ocean-entry footage
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shot on the coast of Kalapana, Hawaii.
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This steamy mist is actually laze,
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a cloud of toxic gas.
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It's made up of hydrochloric acid,
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the result of steam reacting
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with lava-heated salt particles.
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There are also bits of volcanic glass swirling in there.
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The water cools the lava,
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which gets crushed up by the waves into volcanic glass
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and swept up into the plumes.
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Not something you want to be breathing in.
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Lava that doesn't shatter
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will start hardening into a delta,
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an inherently unstable new landmass.
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Blobs of pillow lava pile one on top of the other,
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forming a shaky foundation.
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When water gets trapped among these hot pillows,
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it causes a steamy, violent explosion
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called a molten fuel coolant interaction.
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This can sometimes trigger the whole delta to collapse
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and hurl rock and debris over an area
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as large as multiple football fields.
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Even when the flow looks slow and unthreatening,
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you don't know what's happening under the surface.
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This can apply to the lava itself, too.
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Crystals form as lava cools.
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Generally, the quicker the lava cools,
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the fewer crystals will form and the smaller they'll be.
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But scientists have found
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that bigger crystals with more sides
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slow lava down, giving the lava
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more surface area to cling to as it flows around.
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This is important to understand the lava's viscosity.
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Generally, less viscous flows
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can move faster and travel farther,
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knowledge that helps public-safety engineers
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plan hazard maps.
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So scientists are researching
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how minerals in unique environments
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and unique temperatures create different crystals.
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At Syracuse University, they used metal bits
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of varying size and shapes to represent olivine,
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one of the most common minerals in igneous rocks.
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It has a high crystallization temperature,
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so it can start forming "seeds" in the magma
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even before it leaves the volcano.
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And the seeds will generally keep growing
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as the magma flows out of the volcano
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and slowly starts to cool.
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But when lava cools instantly,
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like when it's suddenly exposed to water or air,
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seeds don't have time to grow.
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This is why igneous rocks like obsidian
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are smooth and glassy.
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And no two volcanoes are exactly the same.
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Time, temperature, and minerals all matter.
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That's especially true when it comes to volcanoes
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on other planetary bodies.
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In 2022, NASA plans to send a spacecraft to Psyche,
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an asteroid between Mars and Jupiter
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that appears to be made of nickel and iron.
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Researchers believe that if Psyche has volcanoes,
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they may be metal-based --
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features called ferrovolcanoes
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that spit up metal instead of silica rock,
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or spurious ferrovolcanoes, which combine the two.
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Ferrovolcanoes are actually still theoretical at this point.
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We know they're possible,
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we just don't know what they'd look like.
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That's why the folks at Syracuse
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decided to make a spurious volcano
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using rock and metal.
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They found that metal moves faster and sinks lower,
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since it's denser than silicate rock.
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This means ferrovolcanoes might look a little different.
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Volcanoes shape themselves
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as layers of lava build up along the sides.
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So a pure ferrovolcano would probably look flatter
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and sprawl farther than the typical conical shape
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we see here on Earth.
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By demonstrating how a ferrovolcano
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would work and look, scientists should be able
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to recognize and interpret formations found on Psyche,
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or any other metal bodies that make up
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the complex geology of our solar system.
