Update: Big Island’s Kīlauea puts on ‘one for the history books’ with Episode 23 of ongoing eruption

Update at 3:15 a.m. May 26: “This is one for the history books!” exclaimed Kelli Veras in her post with a Facebook reel featuring a video of lava fountaining Sunday evening during Episode 23 of the ongoing eruption in Halemaʻumaʻu Crater at the summit of the Big Island’s Kīlauea volcano.

Veras said she was “blown away by the power [and] the beauty of the earth,” and said anyone and everyone — if they were on the Big Island — better not have missed this episode: “Wow. WOW.”

She was one of the many people posting across social media about the latest phase of sustained lava fountaining of the Halemaʻumaʻu eruption that began Dec. 23, 2024, within Kaluapele, the summit caldera of Kīlauea, inside Hawaiʻi Volcanoes National Park.

But for as long as the volcano teased the spectacular geysers of molten rock it ejected to more than 1,000 feet high at times, if you waited to go — or unfortunately got stuck in traffic on your way — you lost your window of opportunity to catch what many described as the best phase of the eruption yet.

Episode 23 ended abruptly at 10:25 p.m. Sunday, just 6 hours and 10 minutes after sustained lava fountaining began at 4:15 p.m., with high geysers starting in the north vent, quickly escalating to more than 1,000 feet high by 5:20 p.m.

The south vent followed lava fountains of about 230 feet by the same time, but geysers increased to more than 800 feet in height at one point.

The north vent stopped erupting at 9:48 p.m. Its sister to the south ceased activity at about 10:25 p.m.

Lava flows covered about half of the Halemaʻumaʻu Crater floor during Episode 23.

The volcanic plume from this eruptive phase was heavily laden with tephra — which is ash, scoria and Pele’s hair — and reached an impressive height of at least 5,000 feet.

The Uēkahuna tiltmeter located at the volcano’s summit recorded about 13 microradians of deflation during this episode.

A rapid change from deflation to inflation at the summit and decrease in seismic tremor intensity coincided with the end of Episode 23.

This behavior has typically marked the beginning of a pause in eruptive activity while the magma chamber underneath the summit recharges and repressurizes.

The East Rift Zone or Southwest Rift Zone of the volcano remain quiet. All eruptive activity is contained within Hawaiʻi Volcanoes National Park.

Kīlauea’s Volcano Alert Level remains at Watch and its Aviation Color Code at Orange.

All eruptive activity is contained within Hawaiʻi Volcanoes National Park.

Hawaiian Volcano Observatory continues to closely monitor Kīlauea and will issue an eruption update tomorrow morning unless there are significant changes before then.

Hawaiʻi County Civil Defense and Hawaiʻi Police Department notified the public Sunday night that Episode 23 lava fountaining was apparently an extremely popular Memorial Day Weekend attraction.

High visitation to Hawai’i Volcanoes National Park — mixed with several major construction projects ongoing inside the park — led to not just traffic delays for people trying to make their way to see Episode 23, but traffic congestion on Highway 11 within the park and as far away as Volcano Village.

Police advised the public to avoid portions of Highway 11 for several hours because of the congestion. Civil Defense told people to expect long delays.

The national park reported in a Facebook post just after midnight today (May 26) that traffic was still “extremely” backed up into the park and on the highway.

However, despite the traffic hassle, if you were one of the lucky ones to make it into the park and see the fountains while they reached to the sky during the most recent eruptive episode before it ended, from what people are saying on social media and the many videos and pictures they are posting, the experience must have been like none other.

“Episode 23 is unquestionably the best episode yet,” says a post accompanying a Facebook reel posted by 808hiker of a video captured Sunday evening of the erupting lava geysers in Halemaʻumaʻu Crater. “Holy moly.”

Original post at 7:52 p.m. May 25: After several days of teasing with precursory activity — which had increased since the morning of May 24 at both vents in the southwest portion of Halemaʻumaʻu Crater within Kaluapele, the summit caldera of Kīlauea volcano on the Big Island — sustained lava fountains finally returned Sunday afternoon.

Episode 23 of the ongoing summit eruption of the volcano inside Hawaiʻi Volcanoes National Park started at 4:15 p.m.

Lava flows are covering the floor of Halemaʻumaʻu Crater.

Fountains from the south vent were about 230 feet tall by 5:20 p.m., while its sister vent to the north was once again pumping out geysers of molten rock exceeding 1,000 feet.

You can check the status of the fountains via three livestream cams provided by the U.S. Geological Survey.

Activity began in the north vent, escalating to high fountains by 4:50 p.m. The south vent followed with smaller fountains by 5:15 p.m.

Inflation at the summit reached just more than 12 microradians since the end of Episode 22 on May 16 and changed quickly to deflation when sustained fountaining began.

Seismic tremor began increasing at 4:36 p.m. Sunday, when lava fountaining increased in height and volume.

Sulfur dioxide emission rates are estimated to be about 50,000 tonnes per day during fountaining events.

As the gas is continuously released during an eruptive episode, it will react in the atmosphere to create vog, or volcanic smog, downwind from Kīlauea, which can cause cause respiratory and other problems at high concentrations.

Additional hazards include Pele’s hair and other volcanic fragments from lava fountains, including tephra.

Pele’s hair — strands of volcanic glass often produced by lava fountaining activity that sometimes cluster and tangle together, giving it the appearance of a tumbleweed — can fall on the ground within a few hundred yards of the eruptive vents or downwind of the vents. Strong winds can even waft light particles, including Pele’s hair, to greater distances downwind.

Most episodes of Halemaʻumaʻu lava fountaining since the ongoing summit eruption began Dec. 23, 2024, have continued for about a day or less and have been separated by pauses in activity lasting generally at least several days.

No changes have been detected in the volcano’s East Rift Zone or Southwest Rift Zone.

Kīlauea’s Volcano Alert Level remains at Watch and its Aviation Color Code remains at Orange. All activity is confined within Hawaiʻi Volcanoes National Park.

Hawaiian Volcano Observatory continues to closely monitor Kīlauea and will issue an eruption update tomorrow morning unless there are significant changes before then.

News reporter Nathan Christophel contributed to this story.