Violent paroxysms at Klyuchevskoy volcano, Aviation Color Code raised to Red, Russia

Activity at Klyuchevskoy volcano in Kamchatka, Russia increased significantly on October 31, 2023, prompting KVERT to raise the Aviation Color Code from Orange to Red. The ash column reached up to 9.8 km (32 152 feet) above sea level and extended for 365 km (226 miles) to the SSE of the volcano.

Klyuchevskoy volcano underwent a significant increase in activity on October 31, according to a Volcano Observatory Notice for Aviation (VONA) issued at 02:34 UTC by KVERT. The Aviation Color Code was raised from Orange to Red, signifying an increased risk to aviation. Satellite data indicated that the ash column ascended to an altitude ranging between 9.5 km and 9.8 km (31 200 – 32 150 feet) a.s.l., extending 192 km (119 miles) to the southwest.

This increased activity was characterized by violent lava fountaining at the summit vent. Jets of lava soared above 500 m (1 640 feet) in height, contributing to the construction of a growing cinder cone within the main crater.

In addition to the summit activity, emissions of fluid and incandescent lava from the southeastern Apakhonchich chute have notably increased. These emissions have formed a lava flow that has extended approximately 3.8 km (2.4 miles) from the summit, reaching an elevation of around 2 700 m (8 858 feet). Concurrently, another arm of active lava continues to erupt from a vent on the volcano’s northwestern flank.

VOLKSTAT volcanologists visually confirmed two instances of debris avalanches on October 28, which were the result of a partial collapse of the unstable crater terrace. This collapse was due to intense summit eruptive activity and led to the formation of a minor pyroclastic flow along the southeastern flank of the volcano. Subsequent to the flow, dense grey ash plumes, termed phoenix clouds, rose several hundred meters above the volcanic structure.

On October 30, 2023, at 20:40 UTC, the Volcanic Ash Advisory Center (VAAC) in Tokyo reported that ash and gas emissions from the summit crater had reached a height of 10 km (33 000 feet) a.s.l. By 05:10 UTC on October 31, the ash plume had extended 365 km (227 miles) to the SSE of the volcano.

At 05:50 UTC on October 31, KVERT stated that ongoing explosive-effusive eruptions continue at the summit, with the potential for ash explosions to reach altitudes up to 12 km (39 400 feet) a.s.l. Such activity poses a significant risk to both international and low-flying aircraft in the region.

Update

00:44 UTC, November 1

Satellite data acquired at 23:10 UTC on October 31 revealed that the ash cloud rose to 14 km (46 000 feet) above sea level and was extending 1 500 km (932 miles) toward the southeast of the volcano.

Ash cloud produced by eruption at Klyuchevskoy reaches 14 km (46 000 feet) a.s.l., Russia

References:

¹ VONA/KVERT Information Release, October 31, 2023. KVERT, Institute of Volcanology and Seismology FEB RAS

² Работы на извержении Ключевского – VOLKSTAT – October 30, 2023

³ Klyuchevskoy volcano (Kamchatka): spectacular paroxysm episode from summit vent continues, two active lava flows and debris avalanches – Volcano Discovery – October 30, 2023

Featured image credit: VOLKSTAT