Hawaiian Volcano Update: Kīlauea Summit Eruption’s Episode 51 - July 16, 2026
After a longer than expected 17-day pause slowed by 3 deflation cycles, episode 51 of Kīlauea’s ongoing summit eruption produced a fan-shaped lava fountain from the north vent on Wednesday, July 15 from 8:30 AM to 4:46 PM, lasting just over 8 hours. Precursory activity began nearly 18 hours earlier with overflows from the north vent first, then the south vent overnight, then back to the north vent followed by the onset of dome fountains from the north vent at 4:47 AM, which slowly grew until the episode began. Lava fountains peaked around 950 feet or 290 meters around 10:30 AM, feeding a plume that rose to 18,000 feet or 5,500 meters above sea level, and 5.1 million cubic meters of lava flows that covered 50% of Halemaʻumaʻu crater floor. Overall, episode 51 continued the pattern observed since episode 44 in April.
“Winds were out of the northeast during the initial hours of fountaining and caused the plume to move toward the southwest during the most energetic part of the episode. High level winds from the south blew the upper plume toward the northwest after 10 AM” according to the USGS Hawaiian Volcano Observatory. “The plume track largely remained within Hawaiʻi Volcanoes National Park with most tephra falling in the closed area,” although reports also note Pele’s hair falling at Uēkahuna overlook and along Highway 11 from Nāmakanipaio campground to the Kaʻū Desert trailhead.
Since the end of the episode, both vents continue to emit roughly 1,000 to 5,000 tonnes of SO2 per day, which while low-level compared to the output during fountaining episodes on the order of 200,000 tonnes, is still much greater than industrial standards and impactful to downwind residents. When trade winds blow, emissions can be carried substantial distances across the south side of the island, wrapping around to the Kona coast. Both during and between episodes, vog and tephra remain the most common hazards for island residents, and the usual precautions and preparations apply, especially for those with respiratory sensitivities – more information at https://vog.ivhhn.org/.
In the 24 hours following episode 51, glow has been noted from both vents while monitoring instruments show recharge of the magma reservoir ahead of another expected episode; however, “more data are needed to determine the forecast” window for the next period of lava fountaining. Over the past 4 months, pauses between episodes have lasted just under 2 weeks on average. As usual, we summarize the monitoring signals, imagery, and reports available courtesy of the USGS Hawaiian Volcano Observatory as well as our broader community, annotating the presentation on-screen and discussing live viewer questions as we go.
