U.S. Geological Survey cameras on the Big Island captured the explosion:
Although the explosion later subsided, the USGS warned that it could restart without any advance warning.
“At any time, activity may again become more explosive, increasing the intensity of ash production and producing ballistic projectiles near the vent,” the agency said Thursday.
Residents of the Big Island are being advised to shelter in place if they’re in the path of the ash plume and to avoid driving in conditions of poor visibility.
Roads coated in volcanic ash can also become extremely slippery.
“During explosive eruptions, volcanic ash can disrupt downwind populations by causing breathing problems, impacting water quality, clogging air filters, shorting out power systems and making transportation difficult,” the USGS warned Thursday.
The agency advised people in the area to seal windows and doors, cover air intakes and open water sources, and remain indoors. Anyone who has to go outside should cover their mouths with a mask or cloth.
The ash plume, which was already 12,000 feet high on Wednesday, soared to 30,000 feet after Thursday’s explosion, according to the USGS.
Also on Wednesday, a vent inside the crater began emitting what the agency calls “ballistic blocks.” The dense, microwave-sized boulders traveled a few hundred yards before coming to rest in a parking lot nearby:
Researchers believe the latest activity may portend more frequent and more powerful steam-driven explosions. Those explosions could be strong enough to launch boulders as large as 12 tons up to half a mile, the USGS said.
The volcano, which began erupting on May 3, has since destroyed 37 homes and other structures. It has also forced the evacuation of around 2,000 residents. Hawaii Volcanoes National Park, where Kilauea is located, has been closed since May 11.