Activity Summary: The summit eruption at Kīlauea volcano that began in Halemaʻumaʻu crater on December 23 ended its 5th episode at 4:30 AM HST January 23 after 26 hours of eruptive activity from the north vent. The 5th episode began at 2:30 p.m. HST January 22 and continued overnight with fountaining to 30-50 m height and Pele's hair observed at the Steaming bluff car park. The 5th episode activity was accompanied by tremor on seismometers, deflation on near vent tiltmeters and gas discharge estimated at greater than 10000 tonnes per day. The fountain activity stopped suddenly at about 4:30 AM HST along with the end of lava effusion from the vent. Seismic tremor diminished at this time and returned to pre- fountaining levels. A strong glow from the north vent indicates that magma remains close to the surface of Halemaʻumaʻu within Kaluapele (the summit caldera). No unusual activity has been noted along Kīlauea's East Rift Zone or Southwest Rift Zone.
Summit Eruption Observations: The Halemaʻumaʻu eruption that began its fifth episode on January 22nd at 2:29 HST which lasted until about 4:30 HST on the 23rd. Fountains fed a lava flow that spread over about one half of the floor of Halemaʻumaʻu crater. Since then, strong glow has continued. Pele's hair was observed at the steaming bluff carpark overnight and may continue to be remobilized by winds within the National Park and in nearby communities over the next few days (see Hazards section below).
Summit Instrumental Observations: Seismic tremor is currently present at low levels. Earthquake activity well below background (one earthquake detected overnight) has been detected in the summit region. Summit tiltmeters showed the onset of a new inflation cycle at about 4:30 HST consistent with the end of fountaining. Tilt increased about 0.2 microradians over the past 2 hours. The most recently measured sulfur dioxide (SO) emission rate was approximately 10000 tonnes per day at the start of episode 5. Though significantly lower than rates measured during eruptive episodes 1, 2, and 3 (Kona winds precluded emission rate measurements during episode 4), this value still represents above-background SO emissions, and the resulting hazard will be affected by wind conditions (see Hazards section below).
View the Kīlauea summit eruption livestream: https://www.youtube.com/usgs/live.
January 15, 2025, Kīlauea summit eruption reference map: January 15, 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. The ESC tiltmeter in the upper East Rift Zone has recorded minor deformation in the last 24 hours. 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 since 2020 within Halema'uma'u crater, which sits inside the southern part of Kaluapele. The recent summit eruptions have lasted from one week to more than a year. Like most of the other eruptions, this event began with vigorous lava effusion and volcanic gas emissions from an initial fissure system. The current eruption is marked by episodic fountaining not seen in any of the other eruptions. There have been four fountaining episodes to date lasting from a few hours to over a week. The onset of fountaining of each episode is accompanied by strong deflation of the summit region. Pauses or periods of repose between all of the fountaining episodes are marked by an immediate change from deflation to inflation of the summit as magma recharge repressurizes the magma chamber. The prior five episodes all began after the Uēkahuna tiltmeter recorded between 6 and 12 microradians of inflationary tilt. The Uēkahuna tiltmeter has recorded about .2-.3 microradians in the 3 hours since episode 5 ended. If this rapid rate of recovery continues, it is possible for another episode to begin as early as the next 3-4 days, but more time is needed to accurately estimate a probability window. The probable window of time for the start of the next episode is based upon behavior prior to previous episodes and could be longer if the inflation rate slows or more pressure is required to initiate the next eruptive episode. (Volcano Watch and Information Statement on episodes and probability windows)
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 (HO), carbon dioxide (CO), and sulfur dioxide (SO) -- are the primary hazard of concern, as this hazard can have far-reaching effects downwind. As SO 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/.
Pele's hair, which are strands of volcanic gas often produced by lava fountaining activity, can be carried by the wind. It can sometimes cluster and tangle together on the ground, giving it the appearance of a tumbleweed. The extent of Pele's hair is dependent on lava fountaining activity and current wind conditions. More information about how Pele's hair is formed is available here: https://www.usgs.gov/observatories/hvo/news/volcano-watch-peles-hairs-a-beautiful-hazard-island-hawaii. A Frequently Asked Questions document developed for the 2022 Mauna Loa eruption includes information about potential health effects of Pele's hair and is available here: https://vog.ivhhn.org/sites/default/files/FAQ_on_air_quality_and_health_during_Mauna_Loa_eruption_v1.6.pdf
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.