Newest Volcano Notice Including Kilauea

Activity Summary:

There were no overflows from either of the Halemaʻumaʻu eruptive vents in the past 24 hours. The summit of Kīlauea has been slowly deflating since Sunday morning, April 5, which may delay the onset of episode 44 lava fountaining to later within the impending forecast window. Further overflows and associated spattering are likely to occur before lava fountaining begins. The current forecast window for episode 44 is between now and April 15.

No significant activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone.

NOTE: The National Weather Service (NWS) issued a Special Weather Statement yesterday about the potential for tephra fall from episode 44 in downwind communities, especially if the episode occurs in the latter half of this week, when the NWS has forecast possible southerly winds.

Significant changes in activity between Daily Updates are posted here: https://www.usgs.gov/observatories/hvo/observatory-messages

Summit Observations:

There were no overflows from either of the Halemaʻumaʻu eruptive vents in the past 24 hours; the most recent was a south vent overflow around 6:00 a.m. HST yesterday morning. Last night, several periods of degassing-related flaming were observed in webcam views of the eruptive vents, and continued strong glow indicates that lava remains close to the surface.

Seismic tremor is continuous with frequent small, poorly defined bursts possibly related to the rise and fall of magma within the vents. 

Summit tiltmeters UWD and SMC have recorded mostly inflation since the end of episode 43, with a switch to slow deflation early on Sunday morning, April 5. By that point, the UWD tiltmeter had recorded about 24.4 microradians of inflationary tilt. Since Sunday, the UWD tiltmeter has recorded a total of about 1 microradian of deflation. 

During eruptive pauses like the one at present, the sulfur dioxide (SO₂) emission rate from the summit has varied within a typical range of 1,000 to 5,000 tonnes of SO₂ per day. Winds have been calm with highly variable directions since yesterday afternoon.

Rift Zone Observations:

Rates of seismicity and ground deformation remain low in the East Rift Zone and Southwest Rift Zone. SO₂ emissions from the East Rift Zone remain below the detection limit.

Analysis:

Rapid rebound of tilt following episode 43 lava fountaining, continued tremor, visible glow, and precursory overflows from the eruptive vents suggest that another lava fountaining episode is likely soon. Further overflows and associated spattering are expected to occur as the onset of episode 44 lava fountaining approaches. Models based on summit inflation indicate that episode 44 lava fountains are likely to begin between now and April 15, with April 7–10 most likely. However, given the summit region deflation since Sunday morning, the start could be delayed to later within the forecast window. 

Kīlauea has been erupting episodically since December 23, 2024, from two vents (north and south) in Halema‘uma‘u. Lava fountaining episodes, which generally last for less than 12 hours, are separated by pauses that can be longer than three weeks.

HVO continues to closely monitor Kīlauea and is in contact with Hawai‘i Volcanoes National Park and the Hawai‘i County Civil Defense Agency about eruptive hazards.

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

Recap of episode 43:

Episode 43 ended at 6:21 p.m. HST on March 10 after lava fountaining continued for just over 9 hours from both vents, sending tephra into surrounding communities. A complete summary of activity can be found here. 

Resources:

NOTE: HVO’s monitoring network is mostly recovered from power and storm related outages. Several summit stations, including the SDH tiltmeter, will remain offline until we are able to re-establish access across the deep tephra field south of the caldera.

The following links provide more information about the current eruption that began on December 23, 2024:

• Eruption resources, including the most recent map and a timeline of eruption episodes since December 23, 2024: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information
• Short messages tracking the evolution of the lava fountains and eruptive activity can be found here: https://www.usgs.gov/observatories/hvo/observatory-messages
• Three Kīlauea summit livestream cameras that show eruptive lava fountains are available here: https://www.youtube.com/@usgs/streams
• Summit eruption webcams: https://www.usgs.gov/volcanoes/kilauea/summit-webcams
• Volcano Watch article on gas pistons: https://www.usgs.gov/observatories/hvo/news/volcano-watch-so-what-earth-or-least-kilauea-a-gas-piston

Hazards:

This episodic eruption is occurring within a closed area of Hawai'i Volcanoes National Park.

• Volcanic Gas: high levels of volcanic gas—primarily water vapor (H₂O), carbon dioxide (CO₂), and sulfur dioxide (SO₂)—are continually released during an eruption. Emissions can remain locally hazardous in the areas immediately downwind of the vents, even when the vents are not actively erupting. SO₂ reacts in the atmosphere to create vog (volcanic air pollution) downwind. SO₂ and vog may cause respiratory and other problems at high concentrations. Further information on vog can be found at https://vog.ivhhn.org/
• Tephra: small glassy volcanic fragments—volcanic ash, pumice, scoria, Pele’s hair and reticulite—are created by the lava fountains. A combination of fountaining dynamics and wind conditions determines where tephra fall may occur for any given eruption episode. Larger particles fall near the vents while light particles may be wafted greater distances. These particles may be remobilized during windy conditions following recent eruptive episodes. Residents and visitors should minimize exposure to these fragments, which can cause skin, eye, and respiratory irritation. More information and guidance on tephra fall hazards is available at https://seagrant.soest.hawaii.edu/resource-and-guidance-for-volcanic-tephra-fall/
• Lava flows: lava on the floor of Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera, remains hot and may slowly move in the days immediately following an eruptive episode.

Other significant hazards exist around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes. Close to the eruptive vents, the tephra material on the crater rim is prone to cracking, slumping, and small landslides that sometimes expose hot and molten material within. This underscores the extremely hazardous nature of Kīlauea's caldera rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since late 2007.