Kīlauea’s 55th Lava Fountain Episode Concludes After Six Hours

Key points

• Episode 55 started at 3:19 a.m. HST on October 17, 2026, following continuous lava overflows that began on October 16.
• The eruption ended abruptly at 9:03 a.m. HST, lasting approximately five hours and 44 minutes.
• Lava fountains reached a maximum height of 720 feet (220 meters), exceeding the 500-foot peak of previous episodes 51 through 54.
• A plume reached 25,000 feet above sea level early in the episode, with tephra detected up to 8,000 feet above sea level.
• All lava and vents remained confined to Halemaʻumaʻu crater within Hawaiʻi Volcanoes National Park.
• The USGS Hawaiian Volcano Observatory kept the Volcano Alert Level at WATCH and the Aviation Color Code at ORANGE.

Background

This event is the 55th fountaining episode since the current Kīlauea summit eruption began on December 23, 2024. Prior to October 17, the volcano experienced a prolonged precursory phase lasting 6.8 days, the longest since the eruption began, characterized by overnight spatter bursts and irregular magma recharge. Recent research suggests steam, rather than carbon dioxide, drives the volcano's dramatic fountains, though predicting exact timing remains difficult due to irregular ground deformation.

How outlets are covering it

Big Island Video News emphasized the visual spectacle of the 720-foot fountains and the plume reaching 25,000 feet, noting that winds from the north-northeast directed volcanic gas and material toward the south-southwest. Big Island Now highlighted the abrupt end of the episode at 9:03 a.m., noting that fountain heights were initially low at 100 to 150 feet before rising. The Honolulu Star-Advertiser focused on the duration, confirming the event ended after nearly six hours. All three outlets agreed that activity was confined to the crater and that the USGS maintained the WATCH alert level.

Why it matters

The record height of the fountains and the prolonged precursory phase indicate significant pressurization within the volcano. While activity remains confined to the crater, the emission of sulfur dioxide and tephra poses local hazards, including respiratory issues and skin irritation for residents and visitors downwind. The irregular timing and height of these episodes underscore the ongoing unpredictability of Kīlauea's behavior.

What to watch

The USGS Hawaiian Volcano Observatory will continue monitoring Kīlauea for signs of further precursory activity or new fountaining episodes. Residents and visitors are advised to minimize exposure to tephra and volcanic gas, particularly in areas downwind of the vents. The crater rim remains closed to the public due to hazards such as ground cracking, rockfalls, and unstable tephra material.