Episode 55 lasted less than six hours on Oct. 17 and could have dropped traces of fine ash and Pele's hair on Pāhala and other Kaʻū communities, while scientists still cannot forecast the next episode.

Kīlauea fountained for the first time in 53 days early Saturday, Oct. 17, with the north vent in Halemaʻumaʻu crater reaching about 720 feet (220 meters) between 4:50 and 5:10 a.m. HST. The episode began at 3:19 a.m. HST and ended abruptly at 9:03 a.m. HST, according to the USGS Hawaiian Volcano Observatory (HVO).

At 9:59 a.m. HST, HVO lowered Kīlauea's Volcano Alert Level from WATCH to ADVISORY and its Aviation Color Code from ORANGE to YELLOW, according to its latest volcano notice. All lava stayed inside the crater within Hawaiʻi Volcanoes National Park, and no homes are threatened.

For people who live downwind, the brief episode still matters. Northeast winds pushed the plume to the southwest, and HVO said traces of fine ash and Pele's hair were possible in Pāhala and other Kaʻū communities, Big Island Video News reported from the observatory's post-episode summary.

A Short, Powerful Episode After the Longest Wait

Nature World News previously reported that USGS could no longer model when the next lava fountain would begin as summit overflows resumed in September. That uncertainty played out exactly as described. Episode 55 arrived without a forecast window and faded within hours.

HVO called the pause before episode 55 the longest and most complex since the eruption began on Dec. 23, 2024. Precursory lava flows started Sept. 7, which was 39 days before fountaining, compared with a previous record of six days. New vents opened along the west side of Halemaʻumaʻu from Sept. 14 to 16, and magma intruded beneath the northwest part of the summit caldera from Sept. 30 to Oct. 1.

The final push came quickly. Continuous overflows from the south vent began at 5:56 a.m. HST on Oct. 16, and the north and west vents joined late that night. Those overflows "appear to have purged the system of older degassed magma," HVO said, letting more gas-rich magma into the conduit to drive the fountain.

Preliminary HVO estimates put the peak eruption rate at about 1,000 cubic yards (770 cubic meters) per second and the total output at about 9 million cubic yards (7 million cubic meters). By 8:30 a.m. HST, lava covered roughly 75 percent of the crater floor. The plume rose to about 25,000 feet above sea level before dropping below 13,000 feet by 7:30 a.m. HST.

Pele's Hair, Tephra and Vog Downwind in Kaʻū

Pele's hair is made of thin strands of volcanic glass spun out of lava fountains, and light pieces can travel long distances on the wind. HVO says tephra falls heaviest within 3 miles (5 kilometers) of the vents, largely inside closed areas of the park. Lighter ash and strands can drift much farther — which is why Kaʻū, not just the summit, is named in HVO's hazard language.

The hazard does not end when fountaining stops. Winds can pick up glassy fragments again in the days after an episode, and "residents and visitors should minimize exposure to these fragments," HVO said, because they can irritate skin and eyes. HVO directs residents to University of Hawaiʻi Sea Grant guidance on tephra fall for cleanup advice.

Gas is the other concern. During fountaining, summit sulfur dioxide emissions typically reach about 100,000 tonnes per day, and HVO expects them to fall back to 1,000 to 5,000 tonnes per day afterward. Sulfur dioxide reacts in the air to form vog, which can cause breathing problems at high concentrations. People with asthma or other lung conditions, older adults and young children in Kaʻū face the greatest risk, and the IVHHN vog resource explains how to limit exposure.

Lava on the crater floor remains hot and may creep slowly for days, and the crater rim remains prone to cracking and small landslides. Park visitors should stay in open areas listed by Hawaiʻi Volcanoes National Park and never enter closed zones for a closer look.

The Alert Drop Does Not Mean Kīlauea Is Done

Under the USGS alert system, ADVISORY signals elevated unrest above background levels, including after activity stops, while WATCH reflects heightened unrest or a limited-hazard eruption underway. The shift reflects the end of fountaining, not the end of the eruption.

The summit began reinflating immediately. HVO's Oct. 18 update said the Uēkahuna tiltmeter recorded 21 microradians of deflation during the episode and had recovered 5.4 microradians since, with steady inflation continuing. HVO has said irregular ground deformation since episode 54 on Aug. 25 prevents forecast modeling for the next episode.

That leaves the central uncertainty unresolved — episode 56 could follow a long precursory phase like episode 55, or it could arrive with little notice. HVO has not said whether future fountains will be larger or smaller.

Residents in Kaʻū should check HVO's daily updates, follow the Sea Grant cleanup guidance if strands or ash collect outdoors, and use the IVHHN advice on days when vog is heavy. Based on current HVO information, there is no reason for most visitors to cancel plans, since lava remains confined to the closed crater area.

The bottom line: episode 55 was short, contained, and over by breakfast, but it showed that Kīlauea can switch on and off with little warning. The next HVO update, not a social media clip, is the best guide to what comes next.

What Readers Want to Know

Is Kīlauea erupting right now?

The summit eruption is paused after episode 55 ended at 9:03 a.m. HST on Oct. 17. Lava remains hot on the crater floor.

What is the current alert level?

HVO lowered the Volcano Alert Level to ADVISORY and the Aviation Color Code to YELLOW at 9:59 a.m. HST on Oct. 17.

What is Pele's hair?

It consists of thin strands of volcanic glass formed during lava fountaining. Light strands can drift long distances and irritate skin and eyes.

Which communities might see ash or Pele's hair?

HVO said traces were possible in Pāhala and other Kaʻū communities southwest of the summit.

When will episode 56 happen?

HVO cannot forecast it because ground deformation has been irregular. The summit began reinflating right after episode 55.

Are homes at risk from lava?

No. All lava has stayed inside Halemaʻumaʻu crater within the national park.