How (Not) To Stop A Volcano

Volcanic eruptions are dangerous. The hot lava that spills from a volcano can burn through anything in its way. Super-hot gas can rush out at hundreds of miles an hour. Landslides can bury everything in their path. Even the ash that rises from a volcano can cause major problems. It can cause people to suffocate. It clogs engines in cars and planes. And if there’s enough of it in the air, ash can even block sunlight so that food can’t grow for hundreds or even thousands of miles around a volcano.

Naturally, with all this disaster, scientists have been trying to work out for years how to stop volcanoes from erupting and prevent all the destruction. Over time ideas have ranged from dropping bombs to using cold water to try and cool lava.

Drop the bomb!

Mauna Loa is a slow-moving volcano in Hawaii. Lava usually flows at around twenty-five miles an hour. That’s the speed a car drives in neighborhoods. It’s slow enough for people living nearby to have time to react before any lava reaches them. In 1935, lava from Mauna Loa was getting close to the Wailuku River. This river supplied water for the town of Hilo. People were desperate to stop the lava before it reached the river.

Engineers and scientists from the US Army suggested that bombs could be used to stop the volcano. They hoped explosions from bombs could collapse the lava tubes (the places where lava flows inside of a hardened lava shell), as well as channels where the lava flowed. They thought that this might open up other paths for the lava away from the river. They dropped 20 bombs to try and redirect the flow.

Unfortunately, the bombs landed too far away from the lava flow. The explosions didn’t change the course of the lava at all. Luckily, the lava stopped soon after the bombs were dropped. It never reached the Wailuku River.

Using explosives to change a volcano might work, if the explosives landed just right. But bombs don’t often fall on their targets. This makes it dangerous to use them in an area where there are people. Detonating bombs in a populated area isn’t a good way to keep people safe! Most scientists and engineers have given up on the idea of using explosives to protect people from volcanoes.

A Cold Shower!

Another way that engineers can try to protect people from lava is by spraying it with cold water. This method mostly worked in Iceland in 1973.

The Eldfell volcano on the island of Heimaey erupted near a town full of people. The residents were able to get away safely, but they wanted to preserve their town. They pumped seawater from around the island directly onto the lava. The water had to be sprayed continuously. It took a lot of seawater and a lot of effort by many people. Even with all this water, the residents couldn’t always stop the lava. One area of lava flow moved too fast to be stopped. The homes and buildings in that area were destroyed. Other areas of the town were buried in ash. But after four months, the volcano stopped erupting. Many people returned to their homes within a year.

Using seawater to stop lava was mostly successful. However, this idea won’t work for all volcanoes. The Eldfell volcano required a lot of water to cool the lava, and many volcanoes are not near an ocean.

New plans

Scientists and engineers are studying yet another way to try and stop a volcano. They’re working on plans to drill down inside a volcano. Magma, the name given to the hot fluid beneath the earth that lava forms from, gathers in chambers far below the surface of the earth. If engineers could reach these chambers, perhaps they could relieve some of the pressure that causes a volcano to erupt. Or, perhaps they could create new paths for the magma to flow that would be out of the way of harming people.

There are many challenges to this plan. It’s hard to dig far down into the earth, and magma chambers are often buried deep. Magma is also so hot that special tools would have to be designed for the high temperature. The whole project would be very expensive. But scientists and engineers are working on ways to overcome these obstacles.

For now, staying far away from a dangerous volcano is the best plan.