Clorox won’t cut it. Volcanologists explain what it takes to clean up after Kilauea

Plumes of smoke, geysers of orange and yellow, fields of red lava rushing over rocks. These are likely what springs to mind when you think of a volcano, dazzling yet devastating. What happens when the eruption is over, though? In 1973, Heimaey, an Icelandic island, was left with a town flooded by ash, the smoldering black particles piles so high that they nearly covered cars completely and reached toward the rooftops.

“In some places volcano cleanup is a daily chore,” University at Buffalo volcanologist Greg Valentine told Digital Trends. “For example, communities around the foot of Sakurajima volcano in Japan have a routine system for cleaning up volcanic ash from explosions that happen a few times a day.”

And as the Kilauea volcano erupts, neighborhoods on Hawaii’s Big Island who don’t lose everything face more of a recovery and not a cleanup, he said.


On April 30, the Puu Oo crater floor on the Big Island began to collapse, triggering earthquakes in Hawaii. Small cracks started appearing in several neighborhood over the next couple of days, and officials warned residents they’d need to evacuate. Since then, several fissures have opened, and dozens of homes have been destroyed. Earlier this week, a massive ash plum exploded from the summit, triggering a hazardous air alert. Now, the volcano is erupting, spewing ash and smoke into the air.

“We are talking about lava that is incredibly sticky and viscous, and that is nearly 2,000 degrees Fahrenheit.”

While Kilauea is one of the United States’ most famous volcanoes and has been active for years, residents on the island didn’t receive much of a warning of the impending increase in activity.

Each volcano is unique, Valentine noted, and warning times may vary. And when it comes down to it, there’s not much that can be done to volcano-proof your home.

“If there is warning time for an eruption, it may be possible to take some action to safeguard homes – but only for some volcanic hazards,” said Joshua Hayes, a Ph.D. Candidate at University of the Canterbury studying disaster recovery planning. “Unfortunately, little can be done to safeguard homes against lava flow or new eruptive vents.”

Fissure 17 from the Kilauea volcano ejects aerial spatter and lava bombs approximately 500ft high. Getty Images

The only thing to do is evacuate, the experts say, or even better, identify high-risk areas and not build there in the first place. But that’s advice that doesn’t do the people on the Big Island any good right now.

“In the Hawaii case, we are talking about lava that is incredibly sticky and viscous, and that is nearly 2000 degrees Fahrenheit,” Valentine said. “No house can stand up to that, and even if it could, it would be partly or completely buried when everything is over.”

Even for homes not in the lava’s path, volcanoes can still do damage. If there are some advanced indicators — such as earthquakes or volcanic gas emissions — homeowners can take some steps to protect against volcanic ash.

A volcanic fissure stands amidst advancing lava in the Leilani Estates neighborhood in the aftermath of eruptions from the the Kilauea volcano. Mario Tama/Getty Images

Closing doors and windows, putting damp towels in the space between doors and floors, taping drafty windows, and storing electronics in sealed plastic bags are all recommended in the International Volcanic Health Hazard Network’s preparedness pamphlet. It also suggests disconnecting drain pipes from gutters so drains won’t clog, while still emptying ash and water onto the ground.

“For volcanic ash, building with high pitched roofs can be beneficial as it allows volcanic ash to slide off rather than settle on the roof,” Hayes said.

Ash aftermath

Eruptions can last years, so it sometimes isn’t safe for residents to return home and start cleanup for a very long time. Because of toxic gases volcanoes can release, “the best approach is to stay away” until authorities give the all-clear, Valentine said.

“Walking into our greenhouse was like walking into a cave.”

When they do return, the task is often monumental and requires the entire community. After Mt. St. Helens erupted in 1980, many local organizations realized they didn’t have ash-removal plans in place. Many people who survived that eruption recall that ash removal was a big hassle.

“When the ash started falling, it was like a snowstorm – the sound was dampened. The next morning it looked like a lunar landscape,” Anne Jacobson Williamson told The Spokane, Washington Spokesman Review in 2010. “Walking into our greenhouse was like walking into a cave; it was dark except for light coming in the end walls. It took a week to wash all the ash from the roof so light could come in again.”

In addition to the volcanic ash, lahar — a muddy mixture that can move quickly down a volcano —  can damage homes, infrastructure, and farmland. The resulting debris might be hazardous (if the buildings contained asbestos, for example) and needs to be removed if residents are going to rebuild in the area, said Hayes, as many of the over 5,000 evacuees did on Heimaey island. Authorities removed over 35 million cubic feet of tephra, or rock fragments and ash from the eruption.

At the foot of the Eyjafjallajokull volcano, firefighters used 40,000 gallons of water to clear ash from the roof of Olafur Eggertsson’s farm after the 2010 blast. More than 50 volunteers used shovels to remove the debris.

“The farm was completely engulfed in ash,” he told NBC News. “It felt like living hell on Earth.”

Experts often use bulldozers and dump trucks for this phase of cleanup.

“Lightly wetting ash and then using a broom to sweep up might be useful, as sweeping dry ash can cause the ash to become airborne,” Hayes said, though there may be water rationing rules in effect. “Small amounts of ash (less than five millimeters thick) can often be left on lawns or in gardens to mix into the soil,” he added.

Residents eager to return to their homes are staying in tents, waiting for the lava to cool.

Unlike dust, volcanic ash is gritty and can scratch surfaces you’re attempting to sweep or wipe down. It can cause respiratory issues, so it may be beneficial to wear a facemask. The International Volcanic Health Hazard Network has some more information about facemasks, which is useful because Googling volcano facemask tends to bring up beauty-related results. Brooms, shovels, and wheelbarrows are all useful tools for homeowners participating in cleanup. If you’re going to use a vacuum, you’ll want to ensure it has a good filtration system and isn’t blowing ash back out.

Sometimes cleanup is interrupted when volcanic activity hasn’t fully subsided, as with Chile’s Calbuco event in 2015. “We were working, cleaning the ash and sand from our homes when this third eruption took place,” Horacio Camano told The Independent at the time. “I feel so much anger and impotence it just breaks me apart.”

kilauea hawaii lava flow street
A lava flow moves on a street after the eruption of Hawaii’s Kilauea volcano Getty Images

Residents eager to return to their homes on the Big Island are staying in tents in the community center’s parking lots, waiting for the lava to cool. That could take months. Leilani Estates, where a small plot of land can cost around $8,000, is made up small houses, often outfitted with solar panels. While some residents removed backup batteries and other valuables, April Buxton told USA Today she didn’t want to tempt the Hawaiian volcano goddess. “I’m not giving up my house to Pele. In my mind, if I empty it, she’ll take it. And if it goes, I’ll lose everything.”

What makes people want to return home after such a devastating event?

“Sometimes it’s stubbornness, but I would say more often than not it’s a lack of alternatives,” Valentine said. “For people whose livelihood is farming on the flank of a volcano, where the soil is rich, and where their community and extended family lives, it’s not so simple to just move somewhere else.”

After Mount Vesuvius destroyed Pompeii, he said, “the landscape became a nice, fertile, vegetated area and people slowly repopulated it.  Now there are more than one million people in the area.”

Updated 5/18/2018: Updated to correct University at Buffalo’s name. 

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