Waves of orange, glowing lava and smoky ash belched and sputtered Monday from the world’s largest active volcano in its first eruption in 38 years, and officials told people living on Hawaii’s Big Island to be ready in the event of a worst-case scenario.
The eruption of Mauna Loa wasn’t immediately endangering towns, but the US Geological Survey warned the roughly 200,000 people on the Big Island that an eruption “can be very dynamic, and the location and advance of lava flows can change rapidly”.
Officials told residents to be prepared to evacuate if lava flows started heading toward populated areas.
The eruption began late Sunday night in the summit caldera of the volcano on the Big Island, the US Geological Survey said. Early on Monday, it said lava flows were not threatening nearby communities.
Ken Hon, scientist-in-charge at the Hawaiian Volcano Observatory, said air quality could deteriorate while the eruption lasted, which scientists expect will be about one or two weeks if the volcano follows historical patterns.
Bobby Camara, a lifelong Big Island resident who lives in Volcano Village, said everyone across the island should keep track of the eruption. He said he had seen three Mauna Loa eruptions in his lifetime and stressed the need for vigilance.
“I think everybody should be a little bit concerned,” he said. “We don’t know where the flow is going, we don’t know how long it’s going to last.”
Officials urged the public to stay away, given the dangers posed by lava, which is shooting 100 to 200ft (30 to 60 meters) into the air out of three separate fissures estimated to be 1 to 2 miles (1.6 to 3.2 km) long.
Volcanic gases wafting out of the vents, primarily sulfur dioxide, are also harmful.
The USGS said it had opened shelters in Kailua-Kona and Pahala because it had reports of people self-evacuating along the South Kona coast.
The USGS said the eruption had migrated to a rift zone on the volcano’s north-east flank. Rift zones are where the mountain rock is cracked and relatively weak, making it easier for magma to emerge.
Gunner Mench, who owns an art gallery in Kamuela, said he had awoken shortly after midnight and seen an alert on his phone about the eruption.
Mench and his wife, Ellie, ventured out to film the eerie red glow cast over the island, watching as lava spilled down the volcano’s side.
“You could see it spurting up into the air, over the edge of this depression,” Mench said. “Right now it’s just entertainment, but the concern is” it could reach populated areas, he said.
The USGS warned residents at risk from Mauna Loa lava flows should review their eruption preparations. Scientists had been on alert because of a recent spike in earthquakes at the summit of the volcano, which last erupted in 1984.
Portions of the Big Island were under an ashfall advisory issued by the National Weather Service in Honolulu, which said up to a quarter-inch (0.6cm) of ash could accumulate in some areas.
“Volcanic gas and possibly fine ash and Pele’s hair may be carried downwind,” Governor David Ige said, referring to glass fibers that form when hot lava erupts from a fissure and rapidly cools in the air. The wind stretches the fibers into long strands that look like hair. “So certainly we would ask those with respiratory sensitivities to take precautions to minimize exposure.”
Mauna Loa is one of five volcanoes that together make up the Big Island of Hawaii, which is the southernmost island in the Hawaiian archipelago.
Mauna Loa, rising 13,679ft (4,169m) above sea level, is the much larger neighbor to Kilauea volcano, which erupted in a residential neighborhood and destroyed 700 homes in 2018. Some of its slopes are much steeper than Kilauea’s so when it erupts, its lava can flow much faster.
During a 1950 eruption, the mountain’s lava traveled 15 miles (24km) to the ocean in less than three hours.