The Weekly Volcanic Activity Report: September 24-30, 2025
New activity/unrest was reported for two volcanoes from September 24–30, 2025. During the same period, ongoing activity was reported for 22 volcanoes.
Dual lava fountains from Kīlauea’s Halemaʻumaʻu crater reach 400 m (1 300 feet), Hawaii
Episode 34 of the ongoing Kīlauea eruption ended at 07:03 HST (17:03 UTC) on October 1, 2025, after 6 hours of lava fountaining from two vents in Halemaʻumaʻu crater at the volcano’s summit, Hawaii. Lava fountains reached up to 400 m (1 300 feet), erupting about 9 million m³ of lava at a peak effusion rate of 500 yd³/s. The eruption filled much of the western crater floor before activity ceased.
Increased seismicity and gas emissions at Meakandake volcano, Hokkaido, Japan
The Japan Meteorological Agency (JMA) raised the Alert Level for Meakandake volcano in Hokkaido, Japan, from 1 to 2 at 06:20 UTC (15:20 JST) on September 15, 2025, after an increase in seismicity near Ponmachineshiri Crater. From September 16 to 23, eruptive activity continued with 27–50 daily volcanic earthquakes, minor ashfall, and white steam-and-gas plumes rising 200–800 m (656–2 625 feet) above the crater rim. Access within 500 m (1 640 feet) of the crater remains restricted, affecting parts of Kushiro City and Ashoro Town.
The Weekly Volcanic Activity Report: September 17-23, 2025
New activity/unrest was reported for 6 volcanoes from September 17 to 23, 2025. During the same period, ongoing activity was reported for 23 volcanoes.
Seismic event linked to renewed eruption at Barren Island volcano, India
A minor eruption was reported at Barren Island volcano in the Andaman Sea at around 10:15 LT (04:45 UTC) on September 20, 2025, two days after a shallow M4.2 earthquake in the region. The National Centre for Seismology suggested the quake may have disturbed the magma system, although no independent confirmation of the link is available.
Lava fountains over 150 m (500 feet) in new eruption at Kilauea, Hawaii
A new eruptive episode started at Kīlauea’s Halemaʻumaʻu crater at 13:11 UTC (03:11 HST) on September 19, 2025, producing lava fountains over 150 m (500 feet) and a volcanic plume up to 3 000 m (10 000 feet) high. The eruption remains confined to the summit caldera within Hawaiʻi Volcanoes National Park.
Kilauea summit showing strong gas pistoning and overflows ahead of next eruptive episode, Hawaii
Kīlauea summit, Hawaii, is showing strong gas pistoning and overflows ahead of the next eruptive episode, with Pele’s hair and volcanic gas already affecting the summit area and nearby communities. The Hawaiian Volcano Observatory (HVO) warns that episode 33 lava fountaining is expected to begin over the next 1 to 3 days.
Spike in seismic activity raises phreatic eruption risk at Kanlaon volcano, Philippines
Kanlaon volcano in Negros Island, Philippines, registered 176 shallow earthquakes on September 15, 2025, raising the risk of a steam-driven eruption. PHIVOLCS maintains Alert Level 2 but and urges communities to avoid the 4 km (2.4 miles) Permanent Danger Zone.
The Weekly Volcanic Activity Report: September 3–9, 2025
New activity/unrest was reported for 5 volcanoes from September 3 to 9, 2025. During the same period, ongoing activity was reported for 21 volcanoes.
Rainfall keeps lahar hazard active at Fuego volcano after initial flows, Guatemala
Weak to moderate lahars descended from Fuego volcano, Guatemala, at 19:17 LT on September 10, 2025, moving through Barranca Ceniza and into the Zarco and Mazate rivers, tributaries of the Achíguate River. The National Institute of Seismology, Volcanology, Meteorology and Hydrology (INSIVUMEH) reported that conditions remain favorable for additional lahars on the southwestern flanks.
