HVO reports increased earthquake activity beneath Halemaʻumaʻu, first notable summit unrest since December 2024
A series of three small earthquake swarms occurred beneath Halemaʻumaʻu crater at the summit of Kīlauea Volcano, Hawaii, between January 13 and 14, 2026, marking the most notable shallow seismic unrest since the eruption’s onset in December 2024. The U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) reports all events were below magnitude 2 and located 1.5–4 km (0.9–2.5 miles) beneath the surface. The activity follows the high fountain eruption of episode 40 on January 12, which produced 5.5 million m³ (7.2 million yd³) of lava within less than 10 hours.
Earthquakes beneath Halemaʻumaʻu crater at the summit of Kīlauea volcano, Hawaii from January 8 to 15, 2026. Credit: TW/SAM, Google
A swarm of volcano-tectonic earthquakes developed beneath the east side of Halemaʻumaʻu crater and the south caldera of Kīlauea volcano, starting around 19:35 HST on January 14 and lasting about 40 minutes before gradually declining in frequency and intensity.
All detected events were below M2, most around magnitude 1, suggesting shallow cracking related to pressurization within the summit magma system.
This was the third such swarm within 36 hours. The first occurred at 00:40 HST on January 13 and lasted about 30 minutes, while the second occurred at 09:10 HST on January 14 and lasted under 30 minutes. All were localized near the shallow Halemaʻumaʻu magma chamber, estimated 1.5–4 km (0.9–2.5 miles) beneath the surface.
HVO scientists classify these earthquakes as volcano-tectonic; events caused by fracturing of rock as magma pressurizes and intrudes into surrounding structures.
Comparable activity levels have not been observed at the summit since the eruption began in December 2024. A previous swarm of similar intensity preceded a new fissure opening in the southern wall of Halemaʻumaʻu crater during episode 30, suggesting that the current unrest could represent early adjustments in the summit plumbing system.
At present, all seismic activity remains beneath Kīlauea caldera, and there is no observational evidence that magma is migrating into the east or southwest rift zones. Ground deformation and gas-emission data suggesting the system remains confined to the summit reservoir complex.
The Volcano Alert Level remains WATCH, and the Aviation Color Code is ORANGE.
The current seismic phase follows the conclusion of episode 40, a high fountain eruption that began at 08:22 HST on January 12, 2026, according to USGS field observations. The episode lasted 9.7 hours, ending at 18:04 HST.
During this event, fountains from the north vent intensified rapidly from 50 m (164 feet) to more than 250 m (820 feet) in height, sending a plume up to 4 000 m (13 120 feet) above the crater floor. Peak instantaneous lava effusion reached approximately 350 m³/s (460 yd³/s) around midday, with an average rate of 190 m³/s (250 yd³/s). The total erupted volume was 5.5 million m³ (7.2 million yd³).
Lava flows covered about 50–60% of the Halemaʻumaʻu crater floor, while the south vent remained open but largely inactive during the high fountain phase. Episode 40 represented one of the most intense effusive events in the ongoing eruption sequence that began in late 2024.
The present seismic swarms are likely the result of internal pressure adjustments following the rapid magma withdrawal during that episode.
Volcanic systems such as Kīlauea maintain a delicate balance between magmatic pressure and the mechanical strength of the host rock. When that balance shifts, even minor weakening can allow magma to intrude new fractures, potentially initiating new eruptive vents or temporarily halting lava fountaining if the magma is diverted laterally.
For now, the summit remains the center of activity, and no changes have been detected in the rift zones.
References:
1 Hawaiian Volcano Observatory information statement for Kīlauea volcano – USGS/HVO – January 14, 2026, 22:05 HST (January 15, 2026, 08:05 UTC).
I'm a dedicated researcher, journalist, and editor at The Watchers. With over 20 years of experience in the media industry, I specialize in hard science news, focusing on extreme weather, seismic and volcanic activity, space weather, and astronomy, including near-Earth objects and planetary defense strategies. You can reach me at teo /at/ watchers.news.
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