HILO >> Alarmingly high levels of volcanic gases early Thursday triggered closure of a half-dozen Puna schools, and authorities began distributing protective face masks in Puna and Kau in the wake of explosive Kilauea Volcano ash eruptions.
So far in this eruption cycle, summit explosions have been preceded by increased earthquake activity, and seismic activity was slowly building again Thursday afternoon, said Jim Kauahikaua, a USGS geophysicist.
Scientists reported a new fissure, No. 21, near Makamae Street in the Leilani Estates subdivision late Thursday afternoon, and activity resumed at several others that were producing pahoehoe lava flows.
Most of the lava that has surfaced in the East Rift Zone since May 3 has been slow-moving aa lava believed to date back to a 1955 eruption in the area. Scientists think that lava had been stored in underground reservoirs for the past 60 years, and those aa flows have tended to be pasty and slow-moving.
Pahoehoe flows such as those that emerged Thursday afternoon, however, are often much more fluid — and sometimes advance more rapidly.
The eruption has destroyed 39 structures so far, but Civil Defense officials say they do not know how many of those buildings were homes.
In activity at the Kilauea summit, scientists reported explosive ash eruptions at about 6 p.m. Wednesday and 4:37 a.m. Thursday.
The event Wednesday night did not trigger any alerts or warnings, but Civil Defense issued a warning at 5:26 a.m. about Thursday’s “explosive eruption,” saying that “the resulting ash plume will cover the surrounding area.”
Authorities urged residents in the path of the plume to shelter in place. There were no injuries reported in the belching of ash.
Scientists with the U.S. Geological Survey reported the blast generated a plume of ash and steam that reached 30,000 feet into the atmosphere. Winds carried ash to the north and northeast.
Linda Ugalde, a 20-year resident of Volcano, said she heard and felt nothing but stepped outside of her home at the Volcano Golf Course subdivision about 10 minutes after the county alert to find a film of dark gray ash coating the railing on her lanai and the plants in her garden and yard.
She compared it to the ash from a fireplace “except smaller.”
“Yesterday was not like this,” she said of the ash. “I had let my dogs out, and I immediately went out to let them back in.”
An ash plume from the caldera was visible from her home about 2 miles away from Halemaumau Crater, but Ugalde said it appeared to be a smaller cloud than Tuesday’s plume that shot ash some 12,000 feet into the air.
“It’s totally weird,” she said. “I mean, I expected there would at least be one of the bigger earthquakes just before, or a boom or something.”
As Ugalde watched from outside her house, she said, the plume above the trees began to spread and moved over her home.
“I’m not going to evacuate. We’ll shelter in place,” she said. She and husband Edward have an enclosed cement catchment water tank and have already sealed it off from the ash, she said.
Free dust masks were distributed by Hawaii County Civil Defense at Cooper Center in Volcano, the Pahala Community Center, the Naalehu Community Center and Shipman Park Pavilion in Keaau to help residents in affected areas protect themselves from inhaling the volcanic ash.
John Bravender, warning coordination meteorologist for the National Weather Service, said rain falling on the ash-coated roads could make for treacherous and slippery driving conditions but predicted most of the residue would fall near the summit.
High-level winds above 10,000 feet could cause light accumulations across Puna and areas east of the summit, but Bravender said it is unlikely ash will fall on the west side of Hawaii island or in Hilo. The wind from the southeast was expected to shift more to the east, which would push ash more to the west today.
Cracks have continued to form and widen in the lower East Rift Zone of Puna, where lava began erupting May 3 — suggesting magma is still moving into the area, said Steve Brantley, deputy scientist-in-charge of the Hawaiian Volcano Observatory.
A sensor used to monitor changes in the surface of the earth moved by about 6 inches in the 24 hours ending Thursday morning as portions of the rift zone shifted. The change was seen as a likely precursor to further eruptions, such as the lava that was produced Thursday afternoon.
Brantley said the surface lava flow from fissure No. 17 has slowed dramatically, advancing less than 150 feet in the past two days. That flow is the longest so far in the eruption in the area near Leilani Estates, and extended for more than a mile toward the ocean.
Gov. David Ige was briefed Thursday at Civil Defense headquarters in Hilo and told reporters the effort to “kill” one of three active geothermal wells at the closed Puna Geothermal Venture power plant near Leilani had begun.
Ige said a crew had started injecting cold water into the first well, and experts were monitoring the effort to determine whether it was working as planned. Authorities intend to pump cold water into all three wells and then insert iron plugs to secure them to prevent any uncontrolled releases of gas or fluids if the wells are damaged by lava or earthquakes.
In Pahoa, elevated sulfur dioxide levels forced the closures of Pahoa High & Intermediate School, Pahoa Elementary and Keonepoko Elementary.
A spokeswoman for the state Department of Health said elevated sulfur dioxide levels were detected at 2.7 parts per million at the old Pahoa fire station — which is now being used as an emergency shelter — at 6:45 a.m. Thursday. The department considers a “red” hazard level to be 1 part per million, and the high reading prompted the school closures.
Newly installed air monitoring equipment near Opihikao had a much higher reading of 10 ppm later in the day, according to the Health Department.
Fenix Grange, program manager for the department’s Hazard Evaluation and Emergency Response program, said that very high sulfur dioxide reading came from equipment that was installed only Wednesday, and the spike in the reading quickly dropped. It was unclear whether that reading was accurate, and other high readings dropped significantly later in the day.
The Hawaii Academy of Arts and Science, Volcano School of Arts and Science, and Na Wai Ola charter school in Mountain View closed Thursday in addition to the Pahoa complex. Kindergarten to fourth-grade classes at Ke Kula ‘o Nawahiokalani‘opu‘u iki were also canceled.