As Mauna Loa Erupts, Officials Warn of Air Hazards

Shelters were opened, parks were closed and health authorities monitored the skies for hazards from smoke, gas and drifting ash after Mauna Loa volcano, located on the Big Island of Hawaii, erupted for the first time in 38 years late Sunday night.

A series of earthquakes preceded the eruption, which took place at 11:30 p.m. on Sunday, spewing lava from the summit inside Hawaii Volcanoes National Park, according to the U.S. Geological Survey. The lava surged to a rift zone on the northeast side of the volcano.

So far there were no warnings for communities to evacuate from the path of the lava flow. Mitch Roth, the mayor of Hawaii County, said two shelters were opened for voluntary evacuations at two gyms, in Kailua-Kona, on the west coast, and in Ka’u, the largest district on the Big Island of Hawaii.

At Kekuaokalani Gymnasium, in Kailua-Kona, there were 56 people taking shelter, most of them migrant workers from coffee farms, said Marty Moran, a disaster program manager for the American Red Cross. Local religious groups brought in food.

“They are in good shape,” he said of those staying at the gym. “We explained to them there was no threat and could go back. There was absolutely no threat to them, but for their comfort and mental well-being, we said we would be open and put them up for the night.”

At the Ka’u shelter, no one showed up at all, he said. Both shelters were scheduled to close at noon, Mr. Moran added.

“We operate in an abundance of caution, and we need to be prepared in case we are needed,” he said.

The Hawaii County Civil Defense Agency on Tuesday designated the volcano an active hazard. Its interactive maps allowed people to determine whether their residences were in an inundation zone.

The Hawaii Department of Health advised residents to stay inside and close doors and windows. Its monitoring stations reported air quality was normal on Monday afternoon, but the department warned that the potential for health hazards from airborne ash, sulfur dioxide and volcanic smog, known as vog, could increase.

“Conditions are changing rapidly, and poor air quality may be very localized,” the department said.

The Parks and Recreation Department said the new eruption was expected to attract visitors. Hawaii Volcanoes National Park was open on Monday, but roads to the volcano and the caldera, a depression in the top of the volcano that forms after an eruption, were closed.