By TOM CALLIS Hawaii Tribune-Herald | Saturday, October 6, 2018, 12:05 a.m.
A large black sand beach remains at Pohoiki. The sand continues to block access to the boat ramp, which is just to the right of the center of the photo. The thick fissure 8 lava flows can be seen in the lower left portion of the image. (U.S. GEOLOGICAL SURVEY/Courtesy photo)
The Hawaiian Volcano Observatory reduced Kilauea’s alert level Friday as the volcano remains relatively quiet following months of devastating lava flows on the lower East Rift Zone and dozens of caldera collapses at the summit.
The change from a watch to an advisory occurred after the passing of 30 days without seeing lava on the surface, along with low rates of earthquakes, ground deformation and only minor gas emissions. There have been no active lava flows since August, though lava was seen inside fissure 8 in Leilani Estates as recently as Sept. 5.
Tina Neal, HVO scientist-in-charge, defined that time scale as weeks or months; she noted they can’t be “super specific” about it.
That doesn’t mean there’s no sign of activity.
Neal said there are signs of inflation, which indicate buildup of magma, on the rift zone between Pu‘u ‘O‘o and Highway 130. She said it’s not “anything we are very concerned about.”
“It’s the most movement, the most inflation we are seeing anywhere on the volcano right now,” Neal said. “It doesn’t look like magma is very shallow. The rate of refilling is not so great that we think it means something is imminent.
One thing is clear: Kilauea remains active and will continue to be monitored closely.
Neal said history shows that eruptions rarely resume at the same location if a pause exceeds 30 days. Outliers include a 48-day pause in 1986 at Pu‘u ‘O‘o and a 3.5-month pause during the Mauna Ulu eruption.
HVO noted in a volcanic activity notice that this is the first time since 1986 that there has been no surface activity for more than 30 days.
“In the past 200 years, the volcano has experienced periods of quiet, ranging from months to years with no eruptive activity,” the agency said. “However, Kilauea is one of the most active volcanoes in the world, and additional eruptions will occur.”
The eruption that began May 3 destroyed more than 700 homes and covered major roads.
Mayor Harry Kim said Tuesday that lava rock won’t be cleared from Highway 137 until the volcano has been quiet for six months, since the rock could still be hot underneath.
But an emergency access road into Pohoiki will be constructed within about two months. In that case, lava rock won’t be cleared, though it would be graded.
HVO lost some of its monitoring equipment because of a brush fire caused by lava flows in the vicinity of Puna Geothermal Venture. Neal said crews will see what can be salvaged or replaced next week.
Placards are still needed to enter Leilani Estates, the epicenter of the eruption.
Email Tom Callis at tcallis@hawaiitribune-herald.com.
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