Aloha, it's your weekly Volcano Minute, brought to you by the USGS Hawaiian Volcano Observatory.

Over the last year and a half, Kīlauea’s summit has produced an impressive 49 episodes of lava fountaining—and episode 50 may be just around the corner. These episodes usually come from one or both of the two persistent vents on the floor of Halemaʻumaʻu crater.

Since December 2024, the eruption has followed a repeating pattern. First, we see hours to days of spattering and small overflows from the vents. Then, a fountaining episode begins. Recently, these fountaining episodes have generally lasted less than 12 hours. After that, surface eruptive activity pauses. But these pauses don’t mean the eruption is over.

So, why are these considered episodes instead of separate eruptions? By definition, an eruption continues as long as magma is still rising and active in the system, even if surface eruption of lava briefly stops. The Smithsonian Institution’s Global Volcanism Program uses a 90‑day pause to mark the start of a new eruption. Kīlauea’s pauses are far shorter, and monitoring data shows the volcano stays active between episodes.

Tiltmeters at the summit record deflation during fountaining and inflation during pauses as magma refills the system below. Seismic tremor associated with fluid movement remains elevated, and gas emissions stay high—much higher than before this eruption began.

All of these signs tell us the eruption is ongoing, and that more episodes are likely. While we don’t know how or when this eruption will end, the volcano’s repetitive patterns continue to give scientists valuable clues about what may come next.

Forecast models currently show that episode 50 could occur between June 23 and June 27.

Mahalo for listening, I’m Katie Mulliken and this was your weekly volcano minute brought to you by the USGS Hawaiian Volcano Observatory.