73
COURTESY HAWAIIAN VOLCANO OBSERVATORY
Hawaiian Volcano Observatory geologists on Wednesday downgraded the alert level for Kilauea volcano from warning to watch for the first time since warning levels were reached in September.
HVO spokeswoman Janet Babb said by phone that aerial thermal images taken by helicopter on Tuesday showed the lower 8 miles of the lava tube, nearest the town of Pahoa, were inactive. "The tube seems to be cooling down in that area — in the lower part of the flow," she said. "All we can say with any certainty is that with each passing day, the likelihood that the tube will be reoccupied by fresh lava is less."
The eruption is continuing at both the Puu Oo vent and in Halemaumau Crater at the summit, the agency said.
The June 27 lava flow is still active, Babb said, but the current breakouts are within 4 miles of the active vent near Puu Oo.
The June 27 flow, currently about 13.5 miles long, is the longest since Kilauea started erupting again in 1983. The leading tip has not advanced any closer than 450 yards to Highway 130 since January.
Since the flow reached the Pahoa area in October, it has crossed a street, flowed into a Buddhist cemetery, destroyed multiple structures, burned a house, and penetrated the fence line of the Pahoa Recycling and Transfer Station. Most of the tenants of the Pahoa Marketplace shopping center have returned.
The Hawaii National Guard was sent to help for about three months, and President Barack Obama declared the lava flow a major disaster.
Babb said the observatory increased the alert level from watch to warning on Sept. 4. "It’s based on the activity," she said. "When we increased the alert level from watch to warning it was because the rate at which the flows were advancing in proximity to areas and infrastructure."
The level was dropped because the threat to homes and infrastructure has been reduced.
But Babb cautioned that circumstances could change.
"If a new vent opens on Puu Oo or if the lava introduction rate increases, things can change quickly," Babb said.
An HVO statement said that if the lava tube heading toward Pahoa Marketplace is reoccupied, lava could reach the leading edge within weeks.
According to the statement, the breakouts from the lava flow are moving slowly atop earlier flows and along the upslope side of the flow that began on June 27 and the Kahaualea flow, which was active in 2013 and 2014.
The observatory estimated it could take months before lava from the breakouts near the active vent could reach within a mile of homes or infrastructure. The observatory also noted it could take months before the lava is one week from homes or infrastructure.
The lava flow direction depends on whether lava predominantly flows from the northern or southern edges of the June 27 lava flow. Lava from the northern margin will likely follow the steepest lines of descent to the Hawaiian Acres and Ainaloa subdivisions. Lava from the southern margin will likely approach the Pahoa area.
Meanwhile, large amounts of sulfur dioxide and other volcanic gases continue to be released into the atmosphere.
After a reconnaissance flight at 11 a.m. Wednesday, Hawaii County Civil Defense said smoke was very light and limited to burning vegetation along the edges of the upslope breakouts. Light, variable winds were blowing the smoke to the south.
