Hawaiian Volcano Update: Kīlauea Summit Eruption’s Episode 23 - May 29, 2025

Episode 23 of Kīlauea’s summit eruption began and ended this past Sunday, May 25, lasting only 6 hours from 4:15 to 10:25 pm. This after a longer than usual pause of 9 days, but to compensate, lava fountains reached their greatest peak yet recorded in these past 5 months, nearly 1,150 feet or 350 meters in height. This was driven by a massive gas plume that likely reached 29,000 feet above sea level, prompting the USGS-HVO to begin issuing aviation notices for each new episode moving forward. Once again, flows crossed the full length of Halemaʻumaʻu crater floor, a distance of 1.33 miles or 2.1 km, covering perhaps half of its area with new lava.

Again following the end of fountains, both vents have exhibited night-time glow while the volcano has been reinflating with magma, with episode 24 expected within the next 3 to 7 days. There continue to be no significant changes on either of Kīlauea’s rift zones.

While trade winds dominant over the past week kept the ground-level fallout of tephra and gas away from viewing areas and nearby communities, the sheer height of the gas column allowed lighter materials like Pele’s hair and reticulite to travel much greater distances, falling widely across the southern part of the island all the way to Ocean View. Vog and tephra hazards have become common to island residents, and the usual precautions and preparations apply, especially for those with respiratory sensitivities – more information at https://vog.ivhhn.org/.

Maunaloa continues to inflate quietly its established post-eruption pattern, with only small-magnitude earthquakes and minor adjustments evident on monitoring instruments. As usual, we summarize the monitoring signals, imagery, and reports for both volcanoes available courtesy of the USGS Hawaiian Volcano Observatory, annotating the presentation on screen as we go and discussing live viewer questions.