Buried by Lava

People in Hawaii are used to living with volcanic eruptions. There are five volcanoes on the Big Island, three of which are active (see Hot Spot). Kilauea itself has been continuously erupting since 1983, though until now it hasn’t caused much drama for Hawaii’s residents. Shield volcanoes like Kilauea usually don’t violently blow their tops. Instead, they slowly ooze lava that flows downhill and hardens to give the volcanoes their low, broad shape. “Most times you can walk or run faster than the lava can flow,” says Alex.

At shield volcanoes, lava erupts from bowl-like craters near their summits as well as from cracks in rift zones, which are areas of weakened rock. “[Rift zones are] like the seam of a baseball. They open up occasionally to let lava through,” says Charles Mandeville, a volcanologist with the U.S. Geological Survey (USGS).

People in Hawaii are used to living with erupting volcanoes. There are five volcanoes on the Big Island. Three of them are active (see Hot Spot). Kilauea itself has been erupting nonstop since 1983. But it hasn’t caused much trouble for local people until now. Kilauea is a shield volcano. This kind usually doesn’t blow its top violently. Instead, shield volcanoes slowly ooze lava that flows downhill. The lava spreads out and hardens. It gives the volcanoes their low, broad shape. “Most times you can walk or run faster than the lava can flow,” says Alex.

The lava from shield volcanoes erupts from bowl-like craters near their summits. It also erupts from cracks in rift zones. These are areas of weakened rock. “[Rift zones are] like the seam of a baseball. They open up occasionally to let lava through,” says Charles Mandeville, a volcanologist with the U.S. Geological Survey (USGS).

Before Kilauea’s recent outburst, Alex had often visited the Halema‘uma‘u [HAH-lay-maohmaoh] crater at the volcano’s summit (see Understanding Kilauea). From there, he could see the crater’s lava lake. But last April, the lake overflowed onto the crater floor.

Around the same time, ground instruments and satellite images revealed the swelling of land around Pu‘u ‘O‘o [POO-oo OH-oh]—a vent, or opening, farther downslope that contained another lava lake. “We were literally seeing the ground inflate,” says Mandeville.

The changes people were witnessing were caused by underground molten rock, called magma, flowing upward into the volcano faster than it could be released aboveground as lava. “We knew that eventually the system would bust open, but we didn’t know where,” says USGS volcanologist Wendy Stovall.

Alex had often visited the Halema‘uma‘u [HAH-lay-maoh-maoh] crater at the volcano’s summit (see Understanding Kilauea). That was before Kilauea’s recent outburst. He could see the crater’s lava lake from there. But last April, the lake overflowed onto the crater floor.

Around the same time, ground instruments and satellite images picked up more warning signs. The land was swelling around Pu‘u ‘O‘o [POO-oo OH-oh]. This vent, or opening, farther downhill contained another lava lake. “We were literally seeing the ground inflate,” says Mandeville.

Underground molten rock, called magma, was causing these changes. It was flowing upward into the volcano faster than it could be released from the ground as lava. “We knew that eventually the system would bust open, but we didn’t know where,” says USGS volcanologist Wendy Stovall. 

On April 30, the floor of Pu‘u ‘O‘o collapsed, and its lava lake drained into cracks and tunnels in the rock below. Magma was on the move.

On May 3, the East Rift Zone of Kilauea burst, causing a fissure to open in one of the worst possible locations: Leilani Estates, a neighborhood of about 1,500 people. Dozens more fissures opened over the following weeks. Rivers of lava oozed from the earth at temperatures as high as 1,200°C (2,192°F). Lava fountains shot more than 60 meters (197 feet) into the air. Luckily, the lava was slow-moving, so people had time to evacuate. But the flows burned everything in their paths, including more than 150 homes, and blanketed the area with black rock that formed from hardened lava.

On April 30, the floor of Pu‘u ‘O‘o dropped. Its lava lake drained into cracks and tunnels in the rock below. Magma was on the move.

On May 3, the East Rift Zone of Kilauea burst. A fissure opened in one of the worst possible places. It was Leilani Estates, a neighborhood of about 1,500 people. Dozens more fissures opened over the following weeks. Rivers of lava oozed from the earth, as hot as 1,200°C (2,192°F). Lava fountains shot more than 60 meters (197 feet) into the air. Luckily, the lava was slow-moving. That gave people time to leave. But the flows burned everything in their paths, including more than 150 homes. They also covered the area with black rock that formed when the lava hardened. 

Scientists have been monitoring the situation since they first detected changes inside the volcano this spring. They’re keeping a close eye on Kilauea so they can provide warnings to residents to help keep them out of harm’s way. Researchers walk up to the front lines of scalding-hot flows near fissures and use tools to figure out how fast and far the lava might travel. They also collect samples of lava to determine its chemical composition. Doing so tells them more about the volcanic activity underground.

Researchers are also watching the volcano’s summit, near Alex’s school. The movement of magma from the summit into the East Rift Zone back in April and May caused the ground at the summit to collapse. The massive rock collapse sent explosions of volcanic ash into the air above the crater and generated thousands of earthquakes. Most of the quakes were too small to notice, but two larger ones rocked Alex’s school, forcing students to evacuate. “The building was swaying,” says Alex. “You could see and feel the earth moving under your feet.” The area is still extremely active.

Scientists noticed the first changes inside the volcano this spring, and they’ve been watching the situation ever since. They’re keeping a close eye on Kilauea so they can provide warnings. That helps keep local people out of danger. Researchers walk up to the front lines of burning-hot flows near fissures. They use tools to figure out how fast and far the lava might travel. They also collect samples of lava to learn its chemical composition. That tells them more about the volcanic activity underground.

Researchers are also watching the volcano’s summit, near Alex’s school. Magma moved from the summit into the East Rift Zone back in April and May. That caused the ground at the summit to drop. The huge rock cave-in sent explosions of volcanic ash into the air above the crater. It also caused thousands of earthquakes. Most of the quakes were too small to notice, but two larger ones rocked Alex’s school. Students had to get out. “The building was swaying,” says Alex. “You could see and feel the earth moving under your feet.” The area is still extremely active. 

Volcanologists monitoring Kilauea must use respirator masks to filter out the toxic volcanic gas sulfur dioxide from the air they breathe. They wear pants and long-sleeve shirts to protect their skin from the searing heat, plus safety glasses and hard hats to shield them from lava, rocks, and ash hurled from the lava fountains. Sudden changes in wind direction can send waves of hot air and falling rock their way. “It can happen quickly,” says Stovall, “so everyone needs to be on high alert.”

Volcanologists must use respirator masks to work at Kilauea. The masks remove sulfur dioxide, a toxic volcanic gas, from the air they breathe. Scientists wear pants and long-sleeve shirts to protect their skin from the extreme heat. They also wear safety glasses and hard hats. This shields them from lava, rocks, and ash thrown from the lava fountains. Sudden changes in wind direction can send waves of hot air and falling rock their way. “It can happen quickly,” says Stovall, “so everyone needs to be on high alert.”

Despite the dangerous conditions, witnessing the volcano’s impact on local residents has been the hardest part for Stovall. “It’s an emotional roller coaster, because you’re out there doing your job, and you’re watching people’s lives being destroyed,” she says.

Scientists have no way of knowing how long Kilauea’s heightened activity will last. Lava flows continue to pave over everything they encounter, forming new land on the Big Island as they’ve done for thousands of years. “You’re watching creation and destruction at the same time,” says Stovall.

But the hardest part for Stovall isn’t the danger. It’s seeing the volcano’s effects on local people. “It’s an emotional roller coaster, because you’re out there doing your job, and you’re watching people’s lives being destroyed,” she says.

How long will Kilauea’s increased activity last? Scientists have no way to know. Lava flows continue to pave over everything they reach. They’re forming new land on the Big Island as they’ve done for thousands of years. “You’re watching creation and destruction at the same time,” says Stovall.