Kīlauea shows off power, beauty on Earth Day with latest fountaining phase

This story was updated at 2:53 p.m. April 22.

The tiny rock among giants in the cosmos we call home is showing off on Earth Day — and just as the weeklong 62nd annual Merrie Monarch Festival swings into full gear — with another amazing display of shear power and mesmerizing beauty from Hawai‘i’s and perhaps the world’s most active volcano.

High lava fountains once again erupted from Kīlauea volcano’s summit within Hawai’i Volcanoes National Park on the Big Island after Episode 18 of the ongoing Halemaʻumaʻu Crater eruption resumed just before 3:30 a.m. today (April 22).

The spectacular show continued for 10 hours and 8 minutes, with lava fountains abruptly stopping just before 1:30 p.m. and both vents ceasing eruption at about the same time.

Lava jettisoned from both vents and then began overflowing from the north vent in the southwest portion of the crater at 3:47 a.m.

Fountains rocketing upward from the south vent to heights of more than 650 feet by just after 4:30 a.m. and 160-plus feet at the north vent, both feeding vigorous lava flows onto the Halemaʻumaʻu Crater floor.

Hawai‘i County Civil Defense alerted residents and visitors alike earlier during the day that south winds were causing volcanic gas and strands of volcanic glass known as Pele’s hair and volcanic fragments called tephra to impact the national park, nearby Volcano village and surrounding areas.

The public was also advised to stay in doors or leave the area.

A look at the U.S. Geological Survey’s livestream V2cam just after 9 a.m. showed fountaining from the south vent could have been reaching even higher.

“High fountains are expected to continue until an inflationary tilt signal returns,” said Hawaiian Volcano Observatory’s daily Kilauea update issued at 10:18 a.m. today.

High volumes of volcanic gas emissions and some minor soggy weather conditions were mostly shrouding the livestream view of fountaining, especially from the U.S. Geological Survey V1cam.

Conditions had cleared out pretty well by just before 11 a.m., revealing fountains remained high.

Hawaiian Volcano Observatory reported in a status report at that time that molten rock had covered about 20% of the crater’s floor. The livestreams showed lava flows still flowing onto the crater floor fast and furious from the vents just after 9 a.m.

Lava covered about 35% of the floor of Halemaʻumaʻu by about shortly after 10 a.m. as the observatory reported in its daily update that fountains from the south vent continued to skyrocket to heights of more than 650 feet.

About 5 million cubic meters of lava were erupted at about 140 cubic meters per second during the fountaining phase of Episode 18.

Lava flows from both vents covered more than 60% of the Halemaʻumaʻu Crater floor before the episode ended Tuesday afternoon.

Volcanic gas emissions were elevated and heightened.

The last sulfur dioxide emission rate measured April 10 was about 1,200 tonnes per day, with typical levels at about 1,000 tonnes per day during previous pauses. However, sulfur dioxide emission rates during previous high fountaining episodes have reached as much as 50,000 tonnes per day.

As the gas is continuously released from the summit, it reacts in the atmosphere to create the visible haze known as vog downwind of Kīlauea.

Sulfur dioxide and vog can — the primary hazards of concern with this ongoing episodic eruption of Kīlauea — can cause respiratory and other problems at high concentrations.

Strong deflation accompanied the onset of lava fountaining and flows. Tremor also increased as fountaining erupted from both vents.

No significant activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone.

The volcano’s U.S. Geological Survey Volcano Alert Level remains at Watch and its Aviation Color Code at Orange.

Visit the Hawai‘i Volcanoes National Park website for visitor information.

Hawaiian Volcano Observatory continues to closely monitor Kīlauea and is in contact with the national park and Hawai‘i County Civil Defense about eruptive hazards.

This was the 18th eruptive episode in the ongoing Halemaʻumaʻu Crater eruption within Kaluapele, Kīlauea’s summit caldera, that began Dec. 23, 2024.

Each episode has lasted from between as little as a few hours to up to more than a week, accompanied by strong deflation of the summit region.

Pauses between fountaining activity have been marked by an immediate change from deflation to inflation as the magma chamber that feeds the volcano recharges and repressurizes, and each break in overall eruptive activity has lasted from less than 24 hours to up to 12 days.

Of all the eruptive phases during this eruption so far, Episode 18 exhibited some of the most different behavior with its extended time gap between precursary activity and onset of high fountaining — which was just a few hours more than an even 5 days.

Precursory activity began just after 9 p.m. April 16 with spattering bursts from the north vent and strong glow from the south vent. Lava began overflowing from the north vent just less than an hour later at about 10 p.m., signifying the start of Episode 18.

Lava flows made it several hundred feet from the vent before activity ended just before 11:30 p.m.

Episode 18 went on hiatus until 7:45 a.m. April 20 when lava fountains of 6 to 10 feet high from the south vent began feeding flows which made it about a third of the way across the crater floor, or about a half-mile, as ground deformation leveled off, but did not begin deflating — a typical sign of the onset of high fountaining in previous eruptive phases.

The episode paused again shortly before 1 p.m. that day after 4 cycles of lava flows from the south vent.

Glow could be seen from both vents overnight, but there was no noticeable spattering or lava overflows after, and ground tilt continued to show inflation.

Tiltmeters at the Kīlauea summit continued to show persistent inflation after the end of Episode 17 the morning of April 9.

The volcano’s summit inflated by 17.5 microradians — greater than the inflation recorded at the beginning of Episodes 16 and 17 each — by the morning of April 21.

Since fountaining started early today, more than 10 microradians of deflation had been measured by shortly after 10 a.m.

Deflationary tilt at the summit recorded 13 microradians during Episode 18 fountaining.

The end of the eruptive phase was also coincident with a rapid change from deflation to inflation at the summit and a rapid drop in seismic tremor intensity, similar to the ongoing eruption’s 17 previous episodes.

News reporter Nathan Christophel contributed to this story.