Hawaiian Volcano Update: Kīlauea Summit Eruption’s Episode 52 - July 29, 2026
Despite the delays caused by 2 deflation cycles, episode 52 of Kīlauea’s ongoing summit eruption arrived more or less “on time” on Tuesday, July 28, with spattering the previous night, the first lava overflow at 10:22 AM, continuous overflow from 1:56 PM, and fountains starting from 7:10 PM growing up to 500 feet or 150 meters high. The rapid rate of re-inflation following the most recent slowdown has not been typical and may have surprised some, as July 27’s USGS daily update projected the next episode likely on July 29 at the soonest. However, once episode 52 began it conformed to the same pattern since episode 44 in April, with the north vent producing lava while the south vent pumped out clouds of gas, with up to 50% of the floor of Halemaʻumaʻu covered by roughly 5 million cubic meters of lava erupted (4.7 million cubic meters for episode 52), and with gas jetting and flaming during the last few minutes before the episode’s end. The episode ended at 2:36 AM today after 7.4 hours under the full moon.
Although the remnants of Hurricane Fausto caused variable winds during the precursory overflow stage as it passed north of the islands, “winds were out of the northeast during the initial hours of fountaining and caused the plume to move toward the south during the most energetic part of the episode. Later in the evening the lower level winds died and the plume became more vertical but did not spread over populated areas. The plume track largely remained within Hawaiʻi Volcanoes National Park with most tephra falling in the closed area,” according to the USGS Hawaiian Volcano Observatory. “Fine ash was noted within public areas” of the National Park, as the heat-driven volcanic plume peaked around 19,000 feet or 5,600 meters above sea level.
Early signals showing an abrupt switch back to inflation, low-frequency seismic pulsing, and continuing glow from both vents suggest another episode is likely, although more data are needed for the USGS-HVO to determine a forecast. Using the rough trend relating the amount of deflation during an episode to the length of the subsequent pause, we can arrive at a rough expectation for episode 53 around August 9 or 10 – as always subject to delay given the natural variations in volcanic processes. Over the past 4 months, pauses between episodes have lasted just under 2 weeks on average.
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/. 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.
