Activity Summary:  The summit eruption at Kīlauea volcano that began on December 23 has been paused since the evening of January 3. Yesterday there were three instances of brief, localized subsidence on the floor of Halema‘uma‘u crater within Kaluapele—the volcano's summit caldera—in the location of one of the vents from the first day of the eruption. Such subsidence might suggest that the magma column feeding the eruption has withdrawn deeper, but continued glow from the northern eruptive vent last night indicates that lava remains close to the surface. No unusual activity has been noted along Kīlauea's East Rift Zone or Southwest Rift Zone.

Summit Instrumental Observations: Seismicity in the summit region remains low, with only 1 small earthquake (below M2.0) detected in the past 24 hours. Seismic tremor remains near background levels, indicating very little activity at the eruptive vents. Summit tiltmeters have been tracking very gradual deflation since the afternoon of Sunday, January 12. The most recently measured sulfur dioxide (SO₂) emission rate was approximately 500 tonnes per day on Friday, January 10. Though significantly lower than rates measured during more energetic eruptive activity, this value still represents above-background SO₂ emissions, and the resulting hazard will be affected by wind conditions (see Hazards section below).

Summit Eruption Observations: Yesterday there were three instances of brief, localized subsidence on the floor of Halema‘uma‘u crater, beginning around 7:45 a.m., 1:45 p.m., and 5:30 p.m. In each instance, subsidence lasted for 60–90 minutes and was followed by refilling from molten lava stored beneath the surficial crust on the crater floor. These events were tracked by HVO's automatic laser rangefinder pointing at the crater floor, which showed elevation fluctuations yesterday, although most of the floor remains stable. In conjunction with deflationary tilt in the summit region, this subsidence might suggest that the magma column feeding the eruption has withdrawn deeper. However, overnight webcam views showed continued glow from the northern eruptive vent, indicating that lava remains close to the surface. Glow at the southern eruptive vent was significantly diminished last night.

View the Kīlauea summit eruption livestream: https://www.youtube.com/usgs/live.

January 2, 2025, Kīlauea summit eruption reference map: January 2, 2025—Kīlauea summit eruption reference map | U.S. Geological Survey.

Rift Zone Observations: Seismicity remains low in both the East Rift Zone and Southwest Rift Zone, with counts of shallow earthquakes at background levels. A M2.9 earthquake occurred yesterday at 10:44 a.m. south of the middle East Rift Zone at a depth of 4.8 miles (7.7 kilometers) below sea level, but it had no obvious effect on volcanic activity. The ESC tiltmeter in the upper East Rift Zone was tracking deflation in association with the summit eruption, but its tilt trend has flattened during the ongoing pause. Deformation rates remain low in the middle and lower East Rift Zone and in the Southwest Rift Zone, as recorded by GPS instruments and tiltmeters.

Analysis: The current eruption at the summit of Kīlauea is the sixth eruption within Kaluapele since 2020. These eruptions in the summit region have lasted from one week to more than a year in duration. Like most of the other eruptions, this event began with vigorous lava effusion and volcanic gas emissions, but it has paused three times. Episodes 2 and 3 of this eruption were preceded by re-inflation of the summit; as such, if the summit's magma chambers repressurize sufficiently, another eruptive episode could occur in the coming days to weeks. Summit eruptions observed over the past 60 years have exhibited vigorous activity in the opening days which can episodically wax and wane, or drop over time to more sustainable low effusion rates, or slowly diminish and end.

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.

Hazards: The eruption has been occurring within a closed area of Hawai'i Volcanoes National Park. High levels of volcanic gas—primarily water vapor (H₂O), carbon dioxide (CO₂), and sulfur dioxide (SO₂)—are the primary hazard of concern, as this hazard can have far-reaching effects downwind. As SO₂ is continuously released from the summit during an eruption, it will react in the atmosphere to create the visible haze known as vog (volcanic smog) downwind of Kīlauea. Vog information can be found at https://vog.ivhhn.org/.

Hawaiian lava flows generally advance slowly downslope, and during this eruption flows have been confined to Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera. Additional hazards include Pele's hair and other volcanic fragments from lava fountains that can fall on the ground within a few hundred yards (meters) of the eruptive vent(s), or on the western caldera rim downwind of the vent(s). Strong winds may waft lighter particles to greater distances downwind, and wind directions are variable. Residents and visitors 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's caldera rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since late 2007.
 
For discussion of Kīlauea hazards, please see: https://www.usgs.gov/observatories/hawaiian-volcano-observatory/hazards.