According to KVERT, the moderate explosive eruption of Zhupanovsky continued and Alert Level Orange was maintained through 8 September. On 1 September visual data detected an ash plume to an altitude of 3,500 m (11,500 ft) a.s.l. drifting NW of the volcano. Satellite data showed ash plumes at 3,500-4,000 m (11,500-13,100 ft) a.s.l. that extended about 85 km in various directions on 28 and 30 August and 1-4 September. Persistent thermal anomalies were detected from the summit area based on satellite images.

KVERT reported three ash plumes drifting SW on 7 September. The plumes were 10 km, 38 km, and 72 km long at 2,500-3,000 m (8,200-9,840 ft) a.s.l. On 8 September, satellite images revealed an ash plume extending 52 km SW from the volcano.

According to the Tokyo VAAC, ash plumes and possible ash plumes were detected by satellite images during 29 August-9 September with the exception of 5 and 6 September. Plume heights were 2,700-11,600 m (9,000-38,000 ft) a.s.l..

Geological Summary. The Zhupanovsky volcanic massif consists of four overlapping stratovolcanoes along a WNW-trending ridge. The elongated complex was constructed within a Pliocene-early Pleistocene caldera whose rim is exposed only on the eastern side. Three of the stratovolcanoes were built during the Pleistocene. An early Holocene stage of frequent moderate and weak eruptions from 7,000 to 5,000 years before present (BP) was followed by a period of infrequent larger eruptions that produced pyroclastic flows. The last major eruption took place about 800-900 BP. Recorded eruptions have consisted of relatively minor explosions from Priemysh, the third cone from the E about 2.5 km from the summit peak.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)