Why Guatemala's Volcano of Fire is so much deadlier than Hawaii's Kilauea

Guatemala's Volcano of Fire has killed at least 75people since it erupted three days ago. The death toll stands in stark contrast to the nearly month-long eruption of the Kilauea volcano in Hawaii, which has also caused massive destruction but has sparedhuman life.

To understand the deadly contrast requires taking a closer look at these twotypes of volcanoes.

The Volcano of Fire and Kilauea have different shapes and different magma, which combine to produce very different kinds of eruptions.

Shield vs. stratovolcano

Shield volcanoessuch as Kilaueaare formed from moving lava that eventually hardened. These volcanoes are typically flat and wide, often with a dome structure resembling a shield lying on the ground.

Stratovolcanoeslikethe Volcano of Fire (Volcan de Fuego), on the other hand, are likely what most people think of when they picture volcanoes. These are towering mountains with pointed peaks. Their eruptions featurevast lava flows down steep slopes.

As a comparison, Kilauea is roughly 1,200 metres tall, while the Volcano of Fire reaches more than 3,700 metres.

Ketchup vs. tomato paste

Just as there are different types of volcanoes, there are also different types of magma the molten rock that lies deep within Earth (it is called lava once it reaches the surface).

The magma of shield volcanoeslikeKilaueahas lower viscosity, meaning it's runnier.

Volcanologist Einat Lev ofColumbia University's Lamont-Doherty Earth Observatory in New York uses a ketchup and tomato paste analogy to explain the differencebetween the magma found in Kilaueaandthe Volcano of Fire.

"If you try to make a pile of tomato paste, it will stand still," she said. "But if you try to make a pile of ketchup, it will spread."

A volcano erupts in Guatemala

6 years ago

Duration 0:46

The Fuego (Spanish for fire) volcano began erupting Sunday, sending columns of smoke and ash 10 km into the air, covering the area with ash

The lava of the shield volcano (Kilauea) spreads out slowly, while the lava of the stratovolcano(Volcano of Fire) is able to pile up in layers, or "strata" a trait that, combined with its shape,has devastating consequences as gas pressure builds.

Under pressure

All active volcanoes produce gases that have the ability to accumulate.

Going back to the ketchup and tomato paste analogy, imaginegas that is unable to get through the thick magma.If you were to take a straw and blow, you'd need more force to get that bubble to erupt.

Because the magma is less viscous in Kilauea, the gases produced have an easier time escaping.

But in the Volcano of Fire, gases are put under enormous pressure and can erupt in violent, sometimes surprising explosions.

"If you're trying to blow bubbles through ketchup or through tomato paste, with one [the ketchup], the bubble would go through, but with the tomato paste, it would kind of blow the whole thing apart,"saidLev, who wason the ground in Hawaii studyingKilauea two weeks ago. "It's the bubbles that drive how big those explosions are going to be."

Kilauea produces what's known asphreatomagmatic explosions. Theseoccurwhen the magma travels through a tube below groundwater. Thiscauses the water to boil instantaneously. Any rock or debris that have fallen into the lava tube arethen ejected when pressure builds up, sending steam, ash, rocks and gas skyward.

The Volcano of Fire producespyroclastic explosions, whichare far deadlier.

These explosions, full of chunks of lava, ash, and volcanic gases, send extremely fast flowsdown the slopes of the volcano, destroying everything in their path. Anyone breathing in the ash and gas are immediately suffocated. People in atown or city within five kilometres of a pyroclastic flow canbe burned and their community's buildings destroyed.

And that'swhat has occurred in Guatemala. Many villagers reportedly found themselves caught in the volcano's trailof destruction with no warning and no time toescape.

This week's eruption isthe deadliestthe country has seen in more than a century.