Kilauea volcano on Hawaii’s Big Island is heading toward its 49th lava-fountain episode, with the U.S. Geological Survey projecting the next burst between June 13 and 19. The forecast follows episode 48, which erupted on June 1 and lasted 9 hours of continuous fountaining from the north vent, sending molten rock roughly 650 feet into the air. That episode broke the record for the most lava-fountaining episodes in any single Kilauea eruption, surpassing the count set during Puʻu ʻŌʻō’s opening years in the 1980s.
Why the 49th episode forecast carries real urgency
The June 13-to-19 window gives residents near Hawaii Volcanoes National Park and aviation operators roughly one week to prepare for renewed ash fall and airspace disruptions. After episode 48 ended at 1:37 p.m. HST, the Hawaiian Volcano Observatory downgraded the Volcano Alert Level from WATCH to ADVISORY and shifted the aviation warning level from ORANGE to YELLOW. Those downgrades signal a pause, not an end. Summit tiltmeters recorded sharp deflation during the episode, and the pattern that has repeated across 48 prior episodes shows that inflation rebuilds pressure in the shallow magma reservoir until the next fountain breaks through.
A COSMO-SkyMed Second Generation interferogram covering May 25 through June 2 captures exactly that cycle. The satellite deformation image shows localized uplift and an episode-end earthquake sequence, both consistent with magma refilling beneath the summit. If inflation continues at the pace visible in successive radar pairs, the interval between episodes 49 and 50 could tighten below the six-to-eight-day average that has characterized recent cycles. A later start for episode 49, say after June 19, would mean more stored pressure and potentially a faster reload for the following event.
For anyone living downwind or planning to visit the national park, the practical question is straightforward: each episode brings light to moderate tephra fall across parts of the summit area, and the aviation color code jumps back to ORANGE during active fountaining. Flights routed near the summit face potential ash-cloud encounters, and park access can be restricted on short notice. Even when lava remains confined to the summit, gas emissions and fine ash can temporarily degrade air quality, especially for people with respiratory sensitivities.
What episode 48 measurements reveal about the eruption’s trajectory
Episode 48 began at 4:40 a.m. HST on June 1 and produced its maximum fountain height of roughly 650 feet, or 200 meters, around 6:30 a.m. HST. The eruption lasted 9 hours of unbroken lava fountaining from the north vent before activity ceased in the early afternoon. Radar-amplitude maps derived from the same COSMO-SkyMed Second Generation satellite pass outline the spatial footprint of fresh lava flows and tephra deposits across the summit, confirming that the new material remains within the existing crater complex.
The record-breaking label is not casual shorthand. The Hawaiian Volcano Observatory confirmed that episode 48 surpassed the episodic fountaining count from Puʻu ʻŌʻō’s opening years, which had stood as the benchmark for Kilauea’s modern eruptive history. The Associated Press reported the same milestone, framing the current eruption as the most prolific sequence of discrete fountain episodes the volcano has produced in a single eruptive period. That distinction matters because it highlights how efficiently magma is moving from depth to the surface, sustaining a repeating pattern instead of a single, prolonged outburst.
Each episode follows a recognizable rhythm. Deflation during active fountaining drains the summit reservoir, fountaining stops, and inflation begins rebuilding pressure. The HVO update page tracks this cycle in near-real time through tiltmeter and GPS data, alongside gas measurements and seismicity. The forecast window for episode 49 is derived from that inflation trend, calibrated against the intervals observed across the prior 48 episodes. As long as the same pattern holds, scientists can estimate when pressure is likely to cross the threshold for another burst.
Episode 48 also reinforces a key aspect of the current eruption: the activity remains strongly focused at the summit, with no evidence in the published data of magma migrating into the rift zones that fed past, more destructive flank eruptions. Seismicity has clustered beneath the summit and upper East Rift, but the bulletins do not describe sustained earthquake swarms or ground cracks that would indicate magma pushing laterally toward populated areas. That distinction underpins the continued emphasis on localized ash, gas, and viewing hazards rather than widespread lava-inundation threats.
Gaps in the data and what to watch through mid-June
Several pieces of the picture remain incomplete. The USGS bulletins describe post-episode inflation qualitatively but have not published precise daily tiltmeter values or numerical inflation rates for the current inter-episode pause. Without those figures, independent verification of whether the reload pace is accelerating requires waiting for the next InSAR pair or a more detailed HVO status report. Tephra deposit volumes and grain-size distributions from episode 48 are similarly described in general terms on the radar maps, with no tabulated measurements available in the published products.
On the community-response side, direct statements from Hawaii County Civil Defense about shelter-in-place protocols or road closures tied to episode 48 do not appear in the primary USGS notices or linked National Weather Service advisories. Visitor-impact statistics and specific park-closure durations for the recent activity are also absent from the scientific summaries. That leaves a gap between the detailed geophysical monitoring and the on-the-ground experience of residents, tour operators, and park staff who must navigate rapidly changing conditions.
Through mid-June, several indicators will help clarify where the eruption is headed. A sharp uptick in shallow earthquakes beneath the summit, combined with renewed rapid inflation on tiltmeters, would point toward an earlier onset of episode 49 within the forecast window. Conversely, a slowdown in inflation or a shift in seismicity toward the rift zones could suggest a more complex evolution, potentially lengthening the pause or redistributing magma away from the current vent.
Gas emissions will be another key signal. Elevated sulfur dioxide output during the pause, even without visible lava, would indicate continued magma supply to shallow levels and a higher likelihood that pressure is building quickly. If gas levels drop markedly while deformation continues, it could mean that magma is ponding at depth rather than efficiently reaching the surface, a scenario that might favor fewer but more intense episodes.
For residents and visitors, the practical guidance remains consistent: expect intermittent ash and gas impacts during each new fountain, stay alert for short-notice changes to park access, and monitor official channels for both scientific and civil-defense updates. The forecast of a 49th episode between June 13 and 19 is not a guarantee of precise timing or intensity, but it is a clear signal that Kilauea’s current eruptive rhythm is still very much in play-and that the summit will likely light up again soon.
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*This article was researched with the help of AI, with human editors creating the final content.
