Another lava flow crossed Pohoiki Road on Saturday, potentially putting Highway 132 in jeopardy.
Talmadge Magno, Hawaii County Civil Defense administrator, said the flow was being fed by two fissures in Leilani Estates and was moving to the northeast. He said it was entering Puna Geothermal Venture’s property but he didn’t think it was going straight toward any well pads.
“We’re pretty confident they are safe,” he said regarding the geothermal wells, all but one of which have been quenched.
“If it went onto the wells I’d think we’d be fine. It’s going to possibly hit PGV property but the wells are in a different direction.”
Magno said the flow was moving slowly and it’s unclear how soon it could reach the highway if it continues on its path.
“We’re making sure our messaging to the public is making them aware that this could possibly happen,” he said.
“We’ll probably be losing another access point out of the lower Puna area.”
Lava already has crossed Pohoiki Road more than once downhill and lava ocean entries are making Highway 137 along the coast impassable.
If Highway 132 is severed, residents to the east of the fissure line would have to rely on Government Beach Road and go through Hawaiian Beaches or Hawaiian Shores subdivisions.
Tina Neal, Hawaiian Volcano Observatory scientist-in-charge, said one lobe from that flow was moving at 30 yards an hour, but she emphasized to take that with a “grain of salt” because flow rates are variable and different fingers of lava move at different rates.
She said sulfur dioxide levels remain high and a change in wind patterns could cause more communities to be impacted by volcanic gas after Sunday. Weaker winds also might mean more ashfall around the summit region as explosive eruptions continue about twice a day, with smaller emissions in between.
One eruption sent ash between 12,000 and 13,000 feet above sea level on Saturday.
Wendy Stovall, a U.S. Geological Survey volcanologist, said the caldera at the summit has subsided 5 feet as the magma column withdraws in response to the lower Puna eruption on Kilauea’s East Rift Zone. That subsidence allows ground water to infiltrate the magma column, helping create steam explosions.
Seismic activity remains high in the summit region with between 250 and 270 quakes occurring within a 24-hour period, she said.
Neal said there is some debate among geologists about how much steam is contributing to the eruptions, some of which are caused by rockfalls and volcanic gas.
Highway 130 remains open to residents at the 14-mile marker because of steaming ground cracks. The state Department of Transportation put plates over the cracks, which are withstanding temperatures as high as 130 degrees.
Still, geologists say they are not seeing signs of an imminent eruption at that site.
That could be indicated by hydrogen sulfide being detected, which would be a result of magma moving up through the water table.
Stovall said in an email Saturday that hydrogen sulfide hasn’t been detected, and the cracks are checked regularly.
“There is carbon dioxide and water vapor,” she said. “The smell that people are reporting is likely from carbonyl sulfide and a mix of other light organics that come from vegetation reaching temperatures higher than their normal point of stasis.”
Two U.S. Marine Corps helicopters are stationed at Hilo International Airport until Monday, along with a crew of 17 Marines, in case of evacuations.
Their mission could be extended, according to Maj. Jeff Hickman of the Hawaii National Guard, who said there are other helicopters, including three HH-60 Pave Hawks, that are available in Hilo.
Neal said the rate of lava entering the ocean at two entry points between Pohoiki and MacKenzie beach parks has decreased. In Leilani, lava from fissure 7 was pumping out a lot of pahoehoe lava and forming a lava pond.
“Of course when it ponds it has the ability to drain rapidly in one direction and move quickly,” Neal said.
Stovall said a lava tube appeared to have been forming on one of the ocean entries, which could keep the flow insulated.
Since the eruption began May 3 on Kilauea’s East Rift Zone, 82 structures have been destroyed with 41 of those confirmed to be homes. Lava has covered at least 2,200 acres.
Email Tom Callis at tcallis@hawaiitribune-herald.com.