HILO — An explosive eruption at Kilauea’s summit — the largest of three this week — ejected ash as high as 30,000 feet above sea level Thursday morning, but had minimal impact on the ground.
The short-lived eruption occurred while most were still asleep and spread a trace or less of ash on nearby Volcano and Pahala. Rainfall appeared to limit its dispersal mostly to around the caldera.
“You’d need a (microscope) to see it, really,” said Louis Daniele, manager of the Ka‘u Coffee Mill in Pahala. “If you rub your hands on the tables outside, you can feel some grit, but you can’t see it.”
Hawaii County officials, concerned there would be a greater impact, had masks distributed to protect residents from ash in Volcano, Pahala, Naalehu and Keaau.
Talmadge Magno, Hawaii County Civil Defense administrator, said the county had 18,000 masks flown in and most were distributed Thursday. The masks don’t provide protection from volcanic gases.
Distribution will continue from 1-7 p.m. today at Cooper Center in Volcano and the Ocean View Community Center. Masks are limited to one per family member.
Dina Shisler, leader of a Community Emergency Response Team distributing “N95” particulate masks in Naalehu and Pahala, said residents downwind of Kilauea are worried, with many wearing surgical masks as a precaution — although Department of Health nurse Deborah Brown emphasized that such masks are no substitute for the dust masks distributed at the station.
Pahala resident Kayo Munnerlyn said she and her son — a student at Volcano School of Arts and Sciences, which has been closed since Friday — have been carrying masks and emergency supplies at all times. Although the air quality was “not that bad” Thursday because of the rain, Munnerlyn said she and her son often developed scratchy throats and headaches since the vog began to worsen. Pahala is located southwest of Kilauea and is often downwind.
At the stations, CERT members and Civil Defense employees passed out information about exposure to ash and toxic gas. In case of ash, residents are advised to remain indoors or in a vehicle, with windows closed and catchment systems sealed. Residents also should pay attention to Civil Defense for notifications on the toxic gas levels in affected areas.
More ejections of ash, potentially with more vigor, are expected as the volcano within Hawaii Volcanoes National Park remains unsettled.
“They are not generating great volumes of ash at this point,” Steve Brantley, Hawaiian Volcano Observatory deputy scientist-in-charge said, regarding recent ash plumes. “We expect to see more energetic activity if this continues.”
Ash is not toxic but can irritate the throat or lungs, and can make for hazardous driving conditions, particularly if mixed with rain.
Kilauea’s summit has seen these eruptions for the past few days as rocks from crater walls fall into its receding magma column. Brantley said the explosions also might be aided by steam from groundwater.
The vertical column of molten rock, which until recently supported a lava lake within Halema‘uma‘u crater, is subsiding in response to the ongoing eruption on Kilauea’s East Rift Zone in lower Puna. That eruption has displaced 2,000 people and destroyed 39 structures so far.
Deflation at the summit has caused the caldera floor to drop by about 3 feet. Brantley said that subsidence is still less than what was seen during explosive events in 1924, that also coincided with a receding magma column and an eruption in Puna, and is not creating additional concern at this time.
The 1924 eruptions occurred over 2 1/2 weeks and hurled blocks weighing as much as 14 tons from the crater. One person was killed then when hit by debris.
The possibility of an eruption of that size has prompted the closure of the park and relocation of HVO staff to the University of Hawaii at Hilo campus.
Brantley said it wasn’t immediately known if rocks were ejected during the Thursday eruption, which followed ash emissions on Tuesday and Wednesday.
Cracks formed on Highway 11 near the park Wednesday due to earthquakes at the summit.
Magno said the road remains open and the state Department of Transportation was conducting repairs.
Email Tom Callis at tcallis@hawaiitribune-herald.com.
Email Michael Brestovansky at mbrestovansky@hawaiitribune-herald.com.