Kīlauea Episode 42 Produces 1,300-Foot Lava Fountains, Ends Same Day

Lava fountains from Halemaʻumaʻu’s summit reached as high as about 1,300 feet from the south vent during Episode 42, which began after continuous overflows across the crater floor and ended at 11:38 p.m. HST on Feb. 15. The U.S. Geological Survey’s Hawaiian Volcano Observatory tied the start of fountaining to seismic and tilt changes at about 13:50 HST following continuous overflows that began at 13:08 HST.

HVO described the onset in technical terms: “Tremor and summit tilt indicate that episode 42 fountaining began at 13:50 pm HST following the onset of continuous overflows at 13:08 pm HST.” Both the north and south summit vents were active through most of the episode, producing sustained fountaining visible on the USGS live-stream feeds and intermittent camera screenshots taken from the caldera rim.

HVO and USGS measurements show the south vent produced the tallest fountains, with HVO placing the south vent between 1,100 and 1,300 feet and the north vent roughly 800 to 1,000 feet. USGS social posts gave metric equivalents of about 400 meters for the south vent and 300 meters for the north vent; a livestream upload from the Mint channel noted fountains up to about 1,200 feet during peak viewing windows.

The episode was intense by several metrics. Star-Advertiser and BigIslandNow reported an instantaneous peak effusion rate of about 1,000 cubic yards per second near 3:00 p.m. HST and an average effusion rate for the episode near 430 cubic yards per second. USGS summarized the eruption’s totals, writing: “Episode 42 at Halemaʻumaʻu (Kīlauea summit) ended at 11:38 PM HST on Feb 15 after 9 hours and 48 minutes of lava fountaining from north and south vents. 🌋 Peak fountain heights: South vent ~400 m (1300 ft), North vent ~300 m (1000 ft). 🌫 Plume reached 35,000 ft above sea level; light tephra (fine ash & Pele’s hair) reported in Pāhala, Punaluʻu, and Nāʻālehu. Volume erupted: ~15 million cubic yards (11.4 million m³), covering ~50% of Halemaʻumaʻu crater floor. 💨 Winds influenced tephra distribution; strong NE trades kept ashfall minimal compared to Episode 41.”

The eruption generated a high-altitude plume that reached about 35,000 feet above sea level, prompting the National Weather Service to issue an ashfall advisory for parts of east and southeast Hawaiʻi Island including Hilo, Pāhoa, Hawaiian Paradise Park and Volcano before canceling the advisory after the episode ended. Ground-level reports and USGS observations described only light tephra and Pele’s hair in southwest communities of Pāhala, Punaluʻu and Nāʻālehu, while strong northeast tradewinds at low levels helped keep heavier fallout away from populated areas.

Officials emphasize continued monitoring. Hawaii Volcanoes National Park closures and USGS live-streaming remained the primary ways to observe summit activity, and the volcano alert level remains at Watch with the Aviation Color Code at Orange. Scientists noted summit cloudiness and rain hampered visual observations during the eruption, and HVO is tracking ongoing summit unrest and will update timing, mapping of crater-floor coverage and any advisory actions as new data are processed.