Kronotsky volcano awakens after a century, sending ash up to 9 km (30 000 feet) a.s.l., Russia
Kronotsky volcano in Kamchatka, Russia, erupted at 03:50 UTC (15:50 LT) on October 4, 2025, ending a century of dormancy. The Kamchatka Volcanic Eruption Response Team (KVERT) reported an explosive eruption with an ash column reaching 9.2 km (30 180 feet) above sea level. Aviation Color Code was raised to Red. KVERT warns that additional ash emissions rising up to 15 km (49 200 feet) remain possible.
Kronotsky volcano, Kamchatka, Russia. Credit: Roskosmos, Oleg Kononenko
An explosive eruption began at Kronotsky volcano, Kamchatka, at approximately 15:50 LT (03:50 UTC) on October 4, according to KVERT. The eruption produced a dense ash column reaching 9.2 km (30 180 feet) above sea level. Satellite analysis indicated that the ash cloud extended about 85 km (53 miles) to the south and southeast, according to Xinhua.
KVERT raised the Aviation Color Code to Red, indicating that a hazardous eruption was underway with significant ash in the atmosphere. The agency stated that further explosive activity could eject ash to 15 km (49 200 feet) at any time.
This marks the first confirmed eruption of Kronotsky in exactly 102 years. The previous eruptive activity occurred in February 1923, following a smaller event in November 1922.
Both eruptions were characterized by explosive and effusive phases and were assigned a Volcanic Explosivity Index (VEI) of 2, indicating moderate explosive energy. Before these events, the last confirmed eruption occurred around 50 BCE and was also classified as explosive and effusive.
The 1923 eruption produced lava flows and ash deposits on the southern flanks of the volcano.
The Institute of Volcanology and Seismology, Far Eastern Branch of the Russian Academy of Sciences (IVS FEB RAS) reported that the 2025 eruption was detected through regional seismic signals and satellite data from Himawari-9, confirming its explosive onset. The initial ash plume height of 9.2 km was followed by fluctuating emissions between 5 km (16 400 feet) and 7 km (22 970 feet), typical of sustained explosive phases.
On the same morning, Shiveluch volcano, about 290 km (180 miles) to the north, produced an ash emission up to 3 km (9 840 feet), according to KVERT. No ashfall or ground-level impacts have been reported in nearby settlements.
Based on the current plume heights, the eruptive strength of the 2025 event is estimated at VEI 2–3, though no official classification has yet been issued. Monitoring continues under the supervision of KVERT and IVS FEB RAS.
The symmetrical Kronotsky stratovolcano lies between the Pacific Ocean and Lake Kronotsky, the largest lake on the Kamchatka Peninsula. The lake formed during the late Pleistocene and early Holocene when extensive lava flows on the southern flank of the volcano dammed the Listvenichnaya River.
The flanks of the massive volcano are deeply incised by radial valleys up to 200 m (656 feet) deep. A volcanic neck plugs the summit crater, and cinder cones are found on the northern, southeastern, and southwestern slopes.
Kronotsky lavas are dominantly basaltic, with the exception of a small basaltic-andesite lava extrusion at the summit and one known flank lava flow. Weak phreatic eruptions occurred during the 20th century.
The volcano is part of the UNESCO World Heritage property “Volcanoes of Kamchatka.”
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Enough events like this and we could see a world wide famine like in the 1300s. That was from so much volcanic ash in the stratosphere that the sun was blocked and no crops could grow.