A powerful explosive eruption took place at Russia's Sheveluch volcano at 17:40 UTC on Sunday, July 23, 2017, producing strong pyroclastic flows. The explosions sent ash up to 12.2 km (40 000 feet) above sea level, according to the Tokyo VAAC. The Aviation Color Code was raised to Red and lowered back to Orange at 22:16 UTC.
Ash plume drifted to the north-east, KVERT said following the eruption, adding at 22:35 UTC that strong gas-steam activity possibly with a small amount of ash continues.
By 22:10 UTC, the ash cloud continued drifting to the north-east. Its front was located about 700 km (434 miles) from the crater, according to Himawari-8 satellite imagery.
Eruption at Sheveluch volcano, Russia on July 23, 2017. Credit: KB GS RAS. Annotation: Culture Volcan
Ash explosions up to 10 - 15 km (32 800 - 49 200 feet) above sea level could occur at any time, KVERT warned. 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 at Sheveluch volcano, Russia on July 23, 2017. Credit: KB GS RAS. Annotation: Culture Volcan