The Weekly Volcanic Activity Report: August 27–September 2, 2025
New activity/unrest was reported for 6 volcanoes from August 27 to September 2, 2025. During the same period, ongoing activity was reported for 23 volcanoes.
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Hurricane Kiko forecast to bring dangerous surf and rip currents to Hawaii
Hurricane Kiko remains a strong category 3 system with maximum sustained winds of 205 km/h (125 mph), moving west at 15 km/h (9 mph). Swells from the storm are expected to reach the Hawaiian Islands late this weekend, producing life-threatening surf and rip currents.
Magma accumulation under Svartsengi nears eruption threshold, Iceland
Around 6 to 7 million m3 (212 to 247 million ft3) of magma have accumulated beneath Svartsengi, Iceland since the eruption on July 16, 2025. At the current rate of accumulation, the estimated threshold of 12 million m3 (424 million ft3) could be reached in the latter half of September, increasing the likelihood of a new eruption.
Moderate M5.9 earthquake hits Chile–Argentina border region
A moderate earthquake registered by the USGS as M5.9 hit the Chile–Argentina border region at 04:10 UTC on September 4, 2025. The agency reported a depth of 176 km (109 miles). EMSC is reporting the same magnitude and depth.
Shallow M6.0 earthquake hits Fox Islands, Alaska
A shallow earthquake registered by the USGS as M6.0 hit Fox Islands, Aleutian Islands, Alaska at 20:57 UTC on September 3, 2025. The agency is reporting a depth of 10 km (6.2 miles).
Cold front triggers severe weather and sharp cooling across parts of the Midwest
A strong cold front is sweeping southeast across the Great Lakes, Upper Midwest, and central Plains on September 3, 2025, bringing temperatures up to 25°C (45°F) below seasonal averages and triggering strong to severe thunderstorms.
Asteroid 2025 QD8 to fly by Earth at 0.57 LD on September 3
A newly discovered asteroid designated 2025 QD8 will fly past Earth at a distance of 0.5 LD (0.00146 AU / 218 351 km / 135 677 miles) from the center of our planet at 14:58 UTC on September 3, 2025.
Lava fountains reach 150 m (500 feet) as Kīlauea eruption episode 32 starts
Episode 32 of the Halemaʻumaʻu eruption at Kīlauea volcano, Hawaii, began at 16:35 UTC (06:35 HST) on September 2, 2025, producing lava fountains up to 150 m (500 feet) high. The eruption remains confined to the summit crater within Hawai‘i Volcanoes National Park.
CME impacts Earth, sparking G2 – Moderate geomagnetic storming
A coronal mass ejection (CME) produced by the August 30, 2025, long-duration M2.7 solar flare impacted Earth at 21:01 UTC on September 1, producing G1 – Minor to G2 – Moderate geomagnetic storm conditions.
Campi Flegrei caldera hit by M4.0 quake in new seismic swarm, Italy
A new earthquake swarm began at 14:09 UTC on August 31, 2025, in the Campi Flegrei caldera, Italy. By 07:30 UTC on September 1, 94 earthquakes were recorded, including a shallow M4.0 event near Pozzuoli at 02:55 UTC.
