Sitting at 4,091 feet, Kilauea volcano shot lava fountains reaching up to 800 feet into the air on April 9, a long-anticipated episode following a week of precursory overflows.
Located on the island of Hawaii alongside four other volcanoes, Kilauea is known for being the smallest but also one of the most active of the group and in the world. Thus, this latest episode, while dramatic, isn’t unprecedented, as the 44th of an ongoing eruptive period that began on Dec. 23, 2024.
“We’re calling them different episodes of the same eruption because it’s the same two vents that have been erupting,” said Katie Mulliken, a geologist and the public information officer for the U.S. Geological Survey’s (USGS) Hawaiian Volcano Observatory. “They just take breaks — anywhere from a week to the last pause, which was actually the longest one we’ve had so far at about a month long.”
George Jensen is a volunteer ranger for Hawaii Volcanoes National Park. He’s witnessed many eruptions and sees the length of this current eruption, approaching two years, as well within the range of past eruptions.
“If you look back on the Pu’u ‘O’o eruption, you’ll see that it started in 1983 and erupted virtually nonstop for 35 consecutive years,” Jensen said. “This one is in kind of the same routine over and over, so they have no idea when it will stop.”
But while these eruptions have been consistent in occurrence, vent behavior has not. For eight hours and 31 minutes, from late morning until just an hour after sunset, activity remained uneven between the two vents.
The north vent sustained continuous fountaining throughout the event, while the south produced only intermittent gas jetting and flames, according to reports from USGS.
“In this last eruption, it was the northern vent that did it, but both the north and the south vents will erupt — sometimes together, sometimes it’s just the north, and sometimes it’s just the south. It does what it wants to,” Jensen said.
Yet USGS noted that, in a flip, of the 75 precursory overflows recorded in the week leading up to the eruption, only four were traced to the north vent.
“We don’t really have a good understanding of why this is,” Mulliken said. “They’re kind of slowly growing in elevation over time because they’re constantly erupting more materials, so we think maybe the elevation has some role to play.”
But Kilauea’s vents during this eruption have varied in more than just activity. While it is currently typically seen with exactly two summit vents, their number has also fluctuated, with episodes from just one, when the north vent buried the south in Episode 28, to as many as three active vents.
“During Episode 30 in August 2025, we started to see some earthquakes on the south wall of the crater, and a small vent actually opened up on that south wall, but it erupted lava only for that episode and never again,” Mulliken said. “So, if we ever see signs of earthquakes during these episodes, that’s always a concern: that another vent could form. That’s something we’re constantly keeping an eye on.”
According to Mulliken, these earthquakes are also often a major indicator of an impending eruption, but these have deviated from the norm this time.
“For these episodes, it’s actually really quiet,” Mulliken said. “We don’t see very many earthquakes for this eruption specifically because the volcano has a really well-established plumbing system between the magma chamber and the surface, so the minute pressure starts to build, rather than earthquakes happening, the vents just erupt lava up. It’s able to move through those pipes and come out to the surface.”
Danger in the spectacle
While considered small compared to its predecessors, episodes 41 through 43, this episode’s single lava fountain still sent an estimated 7.5 million cubic yards of lava flowing downslope and fed a plume of smoke reaching 15,000 feet above sea level.
By noon, this plume became dangerous when shifting southern winds carried its volcanic gas and particles north of the eruption site.
“It goes wherever the wind is blowing. Most of the time, we have winds that take it into a closed area of the national park, so it doesn’t fall on anyone,” Mulliken said. “But we’re in this time of year where we have the opposite wind direction sometimes, towards the areas that visitors are, the highway, and some communities too.”
Visitors in Hawaii Volcanoes National Park reported fragments up to 10 inches in length falling over overlooks, creating hazardous enough conditions — an alert level rise from “watch” to “warning” — to call for both a park entrance closure by USGS and temporary shutdown of 14 1/2 miles of Highway 11 by Hawaii County Civil Defense.
“The highways were coated with what we call tephra,” Jensen said. “The roads were closed because it’s dangerous trying to drive on tephra. It’s like trying to drive on marbles.”
Tephra fallout refers to rocks, glass, and ash ejected into the atmosphere during an eruption, which can cause respiratory problems, driving hazards, and disruptions to air travel, according to USGS. After Episode 44, tephra, including fine ash and Pele’s hair, was seen as far away as Hilo, causing the National Weather Service to issue an ashfall advisory for residents.
“Rocks are falling from the sky. They’re very lightweight and frothy, so they wouldn’t necessarily hurt you too much, but I have seen people with bloody scratches on their arms because it’s a very glassy material,” Mulliken said.
Sarah Williams was in the tephra danger zone, working the front desk at Hawaii Volcano House, the only hotel in the park, built right on the rim of Kilauea.
“It was closed for almost the whole day for the eruption, so I was saddened that guests weren’t able to see it and come into the park. This doesn’t usually happen,” Williams said.
Since hotel guests couldn’t go out during the warning, many turned to the livestream TVs within the building or pressed up against the wall of windows facing the site to see the long-awaited event.
“Lots of people watched it from the livestream here. Unfortunately, there were also lots of people stuck on the road because they closed it down. But for the people who were here, it was very exciting,” Williams said.
For those who do get to experience it in person, that excitement can linger long after the eruption ends. What feels like a once-in-a-lifetime moment often becomes something they keep coming back to, and, for some, a reason to stay.
“I came here to visit my mom and sister, who live here, last summer from Arizona, and I never went home,” Williams said. “The day I got here, the volcano was erupting, so my mom came to take me to see it, and I was just mesmerized. I think it’s the most amazing thing. It’s just incredible every time.”
