When lava meets water, the results are often explosive.
Last year, lava from Hawaii’s Kilauea volcano flowed into the ocean, creating bombs of molten rock that were flung into the sky and smashed into a nearby tourist boat, injuring 23 people.
In 2010, a glacier-covered volcano in Iceland called Eyjafjallajokull erupted and spewed a plume of ash 30,000 feet into the air, causing hundreds of flights in Europe to be grounded.
Scientists want to better understand these reactions to help prepare at-risk communities. And to facilitate their study, researchers brewed their own backyard lava.
“We are not just crazy people mixing and seeing what happens,” said Ingo Sonder, a volcanologist at the University at Buffalo. “We are scientists and we want to quantify, and we do have an idea of what we are doing.”
First, Sonder and his colleagues got black chunks of ancient solidified lava, called basalt, from a quarry in Texas. They poured about 120 pounds of basalt into a crucible inside a furnace. Over four hours, with a few occasional stirs, the furnace heated the rocks to about 2,400 degrees Fahrenheit until the basalt became a bubbling molten mix.
The researchers then poured 10 gallons of glowing goop into insulated steel boxes. The containers varied in size and shape in order to replicate the types of magma columns found in nature.
The walls of the containers had injectors designed to spray pressurized water into the lava. Often, the instant the water hit the lava, it exploded, sending a blazing blob about 6 feet into the air, and a few lava bombs as high as 15 feet. Other times nothing happened, so the researchers used a remotely controlled hammer to trigger the blast.
The team recorded the explosions and published the first of the results, still preliminary, last month in the journal JGR-Solid Earth. It plans to continue brewing lava, experimenting with differently shaped containers and varying amounts of water.