Rocks as big as cars are about to blow from Hawaii’s volcano, scientists predict

Fourteen more lava-filled fissures have erupted in the days since the sloping sides of Hawaii’s Kilauea volcano split open a week ago, spurting molten rock onto the surrounding neighborhoods’ streets and destroying 36 structures. But so far, Kilauea’s summit has yet to blow.

That could soon change, the U.S. Geological Survey (USGS) warned Wednesday night. The volcano’s summit could erupt in the coming weeks, and projectiles as large as two yards in diameter — which USGS volcanologist Wendy Stovall described to VICE News as “automobile-sized” — could fly as far as about half a mile away in all all directions.

As more and more fissures split open, the lava lake inside Kilauea's summit caldera at Halemaʻumaʻu’s “overlook crater” continues to drop. (The caldera, different from a crater, is a sunken basin on a volcano.) If that magma plummets to the level of the groundwater inside Kilauea’s caldera, water could seep into the volcano’s magma. The resulting explosion of steam could rocket gas and rocks upward.

“The whole thing just pops the cork,” in the words of Denison University volcanologist Erik Klemetti.

If that cork does pop, lava likely wouldn’t actually ooze out of Kilauea's summit, since since much of the magna already flowed out through the fissures. But an eruption could send ash and dangerous sulfur dioxide — and, of course, the car-sized projectiles — streaming out.

That ash will just blow downwind, Stovall told VICE News, rather than blanketing the region, as Washington state’s Mt. St. Helen’s did after its eruption in 1980.

When Kilauea’s summit last blew in 1924 the resulting 50-odd eruptions went on for more than two weeks, according to USGS. “Someone was crushed by a block, but they were very close to where the eruption happened,” Stovall said.

As the most active volcano on the Hawaiian islands, Kilauea — which is located on the Hawaii, or the “Big Island” — has erupted continuously for more than 30 years. But those eruptions stayed mostly within the confines of the Hawaii Volcanoes National Park, which Kilauea sits within.

Its most recent fissures, however, have intruded into the nearby neighborhood of Leilani Estates, an area that Kilauea hasn’t touched since the 1950s. More than 1,700 people have now evacuated Leilani Estates. Of the 36 destroyed structures, 26 were homes, according to the Associated Press.

To make matters worse, scientists still aren’t sure what led Kilauea to start erupting at such an aggressive level, Klemetti said. They’re also not sure when the lava will stop.

“This is one of these potential disasters, for the people living there, that is going to be a long-term thing,” Klemetti said. “Volcanoes are like that. They can be a long-term, slow-burn disaster.”

Cover image: An ash plume rises from the Halemaumau crater within the Kilauea volcano summit caldera at the Hawaii Volcanoes National Park on May 9, 2018 in Hawaii Volcanoes National Park, Hawaii. (Photo by Mario Tama/Getty Images)