Kīlauea Eruption Day 2: Several minor fountains remain active within Halema‘uma‘u crater

Kīlauea’s summit eruption continues and is confined to Halemaʻumaʻu crater within Hawai‘i Volcanoes National Park. Hawaiian Volcano Observatory does not see any indication of activity migrating elsewhere on Kīlauea volcano and expects the eruption to remain confined to the summit region.

As of 7:30 a.m., several very minor fountains remain active in the central eastern portion of Halema‘uma‘u crater floor.

Kīlauea volcano began erupting within Halema‘uma‘u crater at approximately 4:34 p.m., following a couple weeks of intermittently elevated summit earthquake activity. Earthquake activity increased dramatically at approximately 3 p.m. on Thursday with increased rates of inflationary ground deformation, prompting HVO to raise Kīlauea’s alert level and aviation color code to WATCH/ORANGE and then to WARNING/RED after the eruption began.

HVO is lowering Kīlauea’s volcano alert level from WARNING to WATCH because the initial high effusion rates are declining, and no infrastructure is threatened. HVO is lowering Kīlauea’s aviation color code from RED to ORANGE because there is currently no threat of significant volcanic ash emission into the atmosphere outside of the hazardous closed area within Hawai‘i Volcanoes National Park.

While fountain heights were initial hundreds of feet high, HVO reports they have decreased in vigor overnight and are consistently about 16 feet high this morning. Lava flows have inundated much of the crater floor, which is nearly 300 acres.

HVO will continue to monitor this activity closely and report any significant changes in future notices.

The higher-elevation island that formed during the initial phase of the December 2020 eruption remains exposed, as well as a ring of older lava around the lava lake that was active prior to December 2022. This older lake has refilled from below with new lava. This morning, the depth of new lava remains at about 32 feet at the base of Halema‘uma‘u crater.

Summit tilt switched from inflation to deflation around 5 p.m. Thursday, and that trend continues this morning. Following the eruption onset, summit earthquake activity greatly diminished and eruptive tremor (a signal associated with fluid movement) resumed. Volcanic gas emissions in the eruption area are elevated.

Hazard Analysis:

The eruption at Kīlauea’s summit is occurring within a closed area of Hawai’i Volcanoes National Park. Therefore, high levels of volcanic gas are the primary hazard of concern, as this hazard can have far-reaching effects down-wind. Large amounts of volcanic gas—primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)—are continuously released during eruptions of Kīlauea volcano. As SO2 is released from the summit, it will react in the atmosphere to create the visible haze known as vog (volcanic smog) that has been observed downwind of Kīlauea. Vog creates the potential for airborne health hazards to residents and visitors, damages agricultural crops and other plants, and affects livestock. For more information on gas hazards at the summit of Kīlauea, see: https://pubs.er.usgs.gov/publication/fs20173017. Vog information can be found at https://vog.ivhhn.org/.

Additional hazards include Pele’s hair and other lightweight volcanic glass fragments from the lava fountains that will fall downwind of the fissure vents and dust the ground within a few hundred yards) of the vent (s). Strong winds may waft lighter particles to greater distances. Residents should minimize exposure to these volcanic particles, which can cause skin and eye irritation.

Other significant hazards also remain around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public. This underscores the extremely hazardous nature of Kīlauea caldera rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since late 2007.

For discussion of Kīlauea hazards, see: https://www.usgs.gov/observatories/hawaiian-volcano-observatory/hazards.

See the Hawaiʻi Volcanoes National Park website for visitor information:  https://www.nps.gov/havo/index.htm.

Visitors to Hawaiʻi Volcanoes National Park should note that under southerly wind conditions, there is potential for a dusting of powdery to gritty ash composed of volcanic glass and rock fragments. These ashfalls represent a minor hazard, but visitors should be aware that such dustings at areas around the Kīlauea summit are possible.