Ocean View residents did not seem particularly reassured following a community meeting regarding a potential Mauna Loa eruption.
Hundreds of citizens packed into the Ocean View Community Center on Saturday to hear a presentation about the likelihood and contingencies for an eruption of the volcano, following weeks of elevated seismic activity, including a magnitude-5.0 earthquake near Pahala on Oct. 14.
HVO Scientist-In-Charge Ken Hon reiterated HVO’s assessment that the seismic activity around the volcano does not indicate a high likelihood of an imminent eruption, and that HVO’s current alert level for the volcano is “Yellow” or “Advisory.”
However, Hon said the volcano is “at the high end of ‘Yellow.’”
HVO geologist Frank Trusdell compared the current seismic activity with records of previous Mauna Loa eruptions in 1975 and 1984. While he noted that those eruptions — the latter of which spewed lava almost all the way to Hilo — were preceded by heightened seismic activity and terrain deformation similar to what HVO has recently detected, he added that HVO has not detected “consistent and persistent” seismicity and deformation.
Hon said that, if that consistent and persistent activity is detected, then HVO will raise its advisory level to “Orange” or “Watch,” which he said would indicate that HVO is reasonably confident that an eruption will occur.
But, even if it becomes clear that an eruption is imminent, Hon said it will be impossible to predict where the lava will flow “until Pele shows us where it will go.” He said that Mauna Loa makes up roughly 50% of the island, and lava can flow in practically any direction from the mountain and threaten any part of the island.
Trusdell said that all 33 recorded Mauna Loa eruptions since 1832 have originated at the volcano’s summit, but 24% flowed into the volcano’s Northeast Rift Zone, toward Hilo, and another 21% flowed the opposite direction, into the Southwest Rift Zone.
This latter path — toward Ocean View — is the most dangerous, as lava flows in Mauna Loa’s Southwest Rift Zone have been recorded to reach the sea in as little as three hours, Trusdell said.
Trusdell added that the lava could erupt from radial vents to the northwest — emerging unpredictably from the ground downslope from the summit, similarly to how lava erupted from Kilauea’s Lower East Rift Zone in 2018. Or, the lava could just stay at the summit and never break out into any flow.
But even if lava erupts at the summit, Trusdell said HVO will not be able to predict where the lava will flow until seismic activity ramps up in a specific direction.
Civil Defense Director Talmadge Magno said the county and partner agencies — including emergency responders, the Hawaii Emergency Management Agency and the Federal Emergency Management Agency — have met to discuss response plans in the event of an eruption. Because of the unpredictability of a lava flow, he urged citizens to be proactive and make emergency plans now.
“You’ve got to fend for yourselves,” Magno said, adding that the county will “take care of what we can,” but if an eruption happens, people should be prepared to move quickly.
This did not sit well with many attendees.
“So, we’re on our own,” one attendee shouted, which was echoed by many others in the audience.
Several attendees asked Magno and other county officials where they should evacuate to in the event of an eruption, but Magno did not have a specific answer, saying that, because nobody knows where the lava will go, nobody can say exactly what the proper evacuation route is.
Magno advised everybody to subscribe to Civil Defense notification services. Should an evacuation be necessary, detailed instructions will be disseminated through those services. He also urged communities to familiarize themselves with their neighbors and understand who may need help evacuating or who may not have internet connections to receive alerts.
Trusdell jokingly suggested that anyone without internet simply look up toward the mountain and, “if you see a reddish glow,” leave, to laughter from the audience.
“It all comes down to common sense, I guess,” said Ocean View resident Chuck Croft. “Don’t think the government’s going to save your ass.”
Croft said he lived in California and Pennsylvania, both of which are prone to their own frequent natural disasters, so he is prepared for an evacuation if necessary, but added that “there’s so many variables, there’s only so much planning you can do.”
Another resident, who asked to remain anonymous, said she thought there needs to be more planning at the county level.
“I don’t think Civil Defense has any of this organized,” she said, adding that she only learned about the meeting about two hours before it happened.
Magno said another meeting on the subject will be held at 5 p.m. Thursday in Pahala.
Email Michael Brestovansky at mbrestovansky@hawaiitribune-herald.com.