A powerful eruption took place at Russia's Sheveluch volcano at 16:31 UTC on August 8, 2017. Ash cloud drifted SSE of the volcano. According to the Tokyo VAAC, ash cloud reached an altitude of 12.2 km (40 000 feet) above sea level.
At 21:20 UTC, the front of the 220 km (137 miles) long ash cloud was located about 360 km (224 miles) SSE of the volcano.
At 03:17 UTC on August 9, KVERT reported that explosive eruption of the volcano was ending, adding that a large ash cloud continues to drift from the volcano. The front was stretching out to the west and east. At 02:30 UTC, its western edge was about 490 km (305 miles) from the volcano, while the eastern edge was about 600 km (373 miles).
Aviation Color Code remained Orange.
The explosive-extrusive eruption of the volcano continues, the agency said and warned that ash explosions up to 10 - 15 km (32 800 - 49 200 feet) a.s.l. could occur at any time. Ongoing activity could affect international and low-flying aircraft.
The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1 300 km3 (311.9 mi3) volcano is one of Kamchatka's largest and most active volcanic structures.
The summit of roughly 65 000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene (5.6 miles) caldera breached to the south. Many lava domes dot its outer flanks. The Molodoy Shiveluch lava-dome complex was constructed during the Holocene within the large horseshoe-shaped caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch.
At least 60 large eruptions have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka.
Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera. (GVP)
Featured image: Eruption of Sheveluch volcano, Kamchatka, Russia on August 4, 2017. Credit: IV FEB RAS, KVERT