Data indicates episode 38 is about to begin. KILAUEA
HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Saturday, December 6, 2025, 8:25 AM HST (Saturday, December 6, 2025, 18:25 UTC)
KILAUEA (VNUM #332010)
19°25’16” N 155°17’13” W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
Activity Summary:
Precursory eruptions began yesterday and episode 38 is about to begin. The rate of summit inflation increased significantly in the past day and overflows began from the north vent just after noon. Continuous overflows began at 3:37 a.m. HST with fountains 20-30 feet (5-10 meters) high. The south vent had strong glow with intermittent spattering overnight. Data indicate episode 38 is about to begin.
Summit Observations:
Precursory eruptions of degassed lava began from the north vent yesterday at 12:50 p.m. HST. The first lasted for less than 2 minutes, but was followed by 3 longer overflows of 10-20 minutes between 5 and 8 p.m. HST last night. The next overflow was another very short one at 2:35 a.m. HST followed by the onset of continuous overflows at 3:37 a.m. HST. There have been two vents clearly separated by a septum of rock since the end of episode 37. The right vent (looking from the V1 camera) is the original vent and the left vent is what remains of the backwall vent prior to episode 37. Initially most of the continuous overflows were originating from the left vent and with a small amount draining back into the right vent and fountaining vigorously. At about 7 a.m. HST the right vent began adding to the overflow and the effusion rate and fountain heights have increased steadily since then. Fountains are currently 20-30 feet (5-10 meters) high and sustained. The north vent is feeding a narrow ribbon-like flow into the center of Halema’uma’u crater. The south vent has continued to glow and spatter intermittently but produced no overflows.
Tremor has been increasing steadily all morning.
As of this morning, about 16.6 microradians of inflationary tilt have been recorded by UWD equaling the deflation during episode 37. The summit is currently deflating.
Rift Zone Observations:
Rates of seismicity and ground deformation remain very low in the East Rift Zone and Southwest Rift Zone. SO2 emissions from the East Rift Zone remain below the detection limit.
Analysis:
Tilt has equaled deflation during episode 37 and currently rapidly rising tremor and deflationary tilt indicate episode 38 is about to begin.
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 previous episode:
Episode 37 fountaining from the north vent stopped at approximately 11:39 p.m. HST on November 25. The south vent was not active during episode 37. Fountains from the north vent reached maximum heights of 500-600 ft (150-180 m). Fountaining lasted for 9.2 hours at an average rate of rate of about 250 cubic yards per second (190 cubic meters per second). Episode 37 produced an estimated 8.2 million cubic yards (6.3 million cubic meters) of lava and covered about 75% of the floor of Halemaʻumaʻu crater. The Uēkahuna tiltmeter (UWD) recorded about 16.5 microradians of deflationary tilt during episode 37.
