The ongoing Halemaʻumaʻu eruption of Kīlauea volcano has reached a historic milestone, with its 47th episode of lava fountaining on May 14, tying the record for the most fountaining episodes ever recorded at Kīlauea, previously held by the initial phase of the 1983-1986 Pu‘u‘ō‘ō eruption. This achievement marks the current eruption as a significant event in the volcano's history, offering unparalleled access to classic Hawaiian fountain displays.
While both eruptions achieved 47 fountaining episodes, the current Halemaʻumaʻu eruption reached this count in just 1.5 years, more than twice as fast as the 3.5 years it took the Pu‘u‘ō‘ō eruption. The average pause between episodes for Halemaʻumaʻu is 10 days, significantly shorter than Pu‘u‘ō‘ō's 24 days. The preliminary magma supply rate for Halemaʻumaʻu is also higher, at approximately 5.8 cubic yards per second, a 25% increase over Kīlauea's long-term supply rate.
Comparing fountain heights presents challenges due to differing measurement techniques; Pu‘u‘ō‘ō measurements included the highest incandescent particles, while Halemaʻumaʻu focuses on the sustained, dense fountain body. Kīlauea Iki holds the record for the highest single fountain at over 1,900 feet. However, the Halemaʻumaʻu eruption is unique for its frequent dual fountains, with episode 43 producing a 1,770 ft fountain from the south vent and a 1,440 ft fountain from the north vent.
The current eruption has also built a cone adding 150 feet to the crater rim's elevation, and the vent height has risen over 500 feet from the crater floor since December 2024. This visibility and accessibility have garnered worldwide attention, making it a memorable event. Following the 47th episode, summit region inflation suggests that another fountaining episode, episode 48, is likely to begin between May 24 and May 26.