UH Hilo geologist Steven Lundblad explains the current on-and-off towering eruptions at Kīlauea
Prof. Lundblad, who researches active lava flows on Hawaiʻi Island, sees “a sawtooth pattern”: the ground tilt increases over the course of a week or so, an eruption happens, it drops, and then immediately starts to rebuild again.
By Susan Enright/UH Hilo Stories.
As of this morning, the ongoing Halemaʻumaʻu eruption is currently paused with Episode 23 ending on Saturday.
Steven Lundblad, a geology professor at University of Hawaiʻi at Hilo, says the repetitive on-and-off eruptions at Kīlauea that started in December are due to pressure build-up of underground lava that has nowhere else to go.
Lundblad’s area of expertise and research is in geochemistry, notably in investigating the chemical composition of Hawaiian stone tools (without any damage to the artifacts) and of active lava flows on Hawaiʻi Island.
- Learn more about Prof. Lundblad’s research (Keaohou website/UH Hilo)
According to the U.S. Geological Survey website, Kīlauea’s current eruption in Halemaʻumaʻu crater within Kaluapele (the summit caldera) began on December 23, 2024, and there have now been 23 episodes separated by pauses in activity.
“What tends to happen is the pressure builds up below the summit of Kīlauea because there isn’t an outlet,” explains Lundblad about the on-and-off eruptions. “At some point the magma makes it to the surface and since it has a fair amount of trapped gas in it, it is erupted out in a fairly explosive manner. We’ve had fountains up to 1,000 feet high during some of the episodes.”
Lundblad says that gas is released and some of the pressure is released, the lava comes out and then tends to cap over the top, and the cycle restarts. It’s a repeatable pattern where about once a week there is an eruptive cycle. In between there’s enough of a cap on the magma chamber to start building up pressure again.
Scientists are tracking the events through studying a host of different effects and parameters of the activity, measuring to both predict when the eruption might occur again but also to learn about what happened during the eruption.
“Currently, the best indicator of what’s happening with the eruption and whether or not it’s going to erupt is the ground tilt and that’s essentially measuring the deformation of the ground surface,” Lundblad says. “You can think of it like a balloon where as the pressure increases the surface moves up and expands.” To visualize this process, he says imagine the ground tilt being related to blowing up a balloon where the pressure is building and the ground surface moves up and away from the summit and causes the ground to be higher in some places than it would be otherwise.
“What seems to happen is when it reaches a certain level of tilt then we get an eruption and the cycle starts over,” he says. “The ground deformation graphs at this point show kind of a sawtooth pattern where the ground tilt increases over the course of a week or so. The eruption happens, it drops and then immediately it starts to rebuild that tilt or the ground deformation again.”
How UH Hilo scientists work on forecasting future eruptions
Another type of investigation that scientists do during eruptions is collect samples; USGS Hawaiian Volcano Observatory scientists do this.
“What we do here at UH Hilo is help them by looking at the chemical composition of the material that comes out to see how the eruption is evolving over time,” says Lundblad. “And so that’s a little bit of a way to predict the longer-term processes that might be going on for future eruptions whether within this eruption cycle or down the road and how they compared to last month, last year, five years ago, 10 years ago and what might be changing at the volcano.”
Professor Lundblad says the current eruption is an interesting one because it follows a similar pattern to some of the longer live eruptions at Kīlauea.
When Puʻu ʻŌ’ō started erupting in 1983 and it erupted for 35 years, the first initial phases of that eruption had many high fountaining episodes before settling down into a pattern with lava flows coming out and then running down to the ocean. “Many people are familiar with that because it was a great place to go look at lava,” he says.
The same thing happened in 1959 at Kīlauea Iki.
“That eruption occurred for about a month or so and it was punctuated by a whole series of high fountaining events,” Professor Lundblad says. “And then in 1969 at Mauna Ulu, again the early phases of that eruption had kind of this episodic high fountaining event.”
“So it’s possible that the volcano will continue to erupt at the summit for a long period of time,” the professor summarizes. “And maybe we won’t see the similar type of high fountaining but we may just continually have lava flows building up the lava lake that exists there.”
See full transcript and video of interview with Prof. Lundblad at UH System News.
Story by Susan Enright, public information specialist for the Office of the Chancellor and editor of UH Hilo Stories. She received her bachelor of arts in English and certificate in women’s studies from UH Hilo.
