USGS: Mauna Loa and Kilauea no longer erupting; alert levels downgraded

HILO (HawaiiNewsNow) - Roughly two weeks after Mauna Loa started erupting ― sending up fountains of lava as high as 500 feet and creating stunning lava rivers that moved downslope ― the volcano has gone quiet.

The U.S. Geological Survey announced Tuesday morning that Mauna Loa is no longer erupting.

The alert level, meanwhile, has been downgraded to advisory while the aviation code is yellow.

“There’s no historical analogue here in Hawaii for a Mauna Loa rift eruption pausing in the middle and then restarting, so we feel pretty confident that this eruption has in fact paused and is probably over,” said Hawaiian Volcanoes Observatory Scientist-In-Charge Ken Hon, in a Tuesday morning briefing.

Scientists said the lava supply to the Fissure 3 vent actually ceased on Saturday.

“All of the lava that was in the channels began draining out, there was no new lava observed entering the channels,” Hon said. “It was all contained within the cones sitting at the vent.”

He added there is steady inflation of the mountain as magma is filling up in the chamber.

Sulfur dioxide emissions have also dropped to near pre-eruption levels. And USGS added that volcanic tremors and earthquakes associated with the eruption have “greatly diminished.”

The eruption started Nov. 27 and it was contained to a largely unpopulated area.

The biggest concern from the eruption was that lava would eventually reach the Daniel K. Inouye Highway, which connects Hilo and Kona. But as lava moved to flatter terrain it slowed and then stopped, well short of the road.

Before the eruption, the 13,681-foot Mauna Loa volcano had been rumbling more and more in recent montsh.

The last time Mauna Loa erupted was in 1984.

Over the course of the latest eruption, scientists said about 200 to 250 million cubic meters of lava was ejected.

Hon said that’s about a fifth of the lava spewed out during the 2018 eruption of Kilauea.

While the Mauna Loa eruption has ended, scientists said spots of incandescence may remain near the vent, along channels and at the flow front for days or weeks as the lava flows cool.

Hon explained an interesting note about this eruption is that the amount of material erupted was roughly the same as past eruptions ― even though the volcano was quiet for 38 years.

HVO said it continues to closely monitor Mauna Loa for signs of renewed activity.

Meanwhile, USGS also reported that Kilauea is no longer erupting at Halemaumau Crater.

The alert level for that volcano has been downgraded to advisory and yellow as well.

Lava supply to the Halemaumau lava lake ceased on Dec. 9 — a day before lava supply ended on Mauna Loa’s Fissure 3. Scientists said while the two volcanoes are independent, it’s not completely clear whether there’s any link between the Kilauea and Mauna Loa volcanoes.

“The volcanoes are not directly connected, but might ‘feel’ one another via stress effects,” the USGS said, in a Twitter thread. “Mauna Loa’s eruption could have allowed Kilauea to ‘relax.’ That said, Kilauea’s eruption was already pretty tenuous, occurring at very low rates.”

Hon added: “Kilauea may have been diminishing already, and Mauna Loa eruption may have caused enough physical changes to stop it — or it may have just been headed to stop on its own.”

“We don’t really have a good answer for that right now, but over the next year or so we are going to be combing through a lot of this data and see if we can learn more about the relationship between these two volcanoes.”

CONTINUING COVERAGE:

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• HVO: Lava spewing from Mauna Loa is not left over from 1984 eruption

With the lowered alert level at Mauna Loa, Hawaii Civil Defense also announced the detour route to view the lava will be scaling back its hours starting Wednesday from 4 p.m. to midnight.

The route will close permanently on Thursday at midnight.

For details on volcano hazard zones, click here.

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