KVERT reported that moderate explosive activity at Zhupanovsky continued during 10-17 July. A strong explosion on 12 July produced an ash plume that rose to an altitude of 10 km (32,800 ft) a.s.l. and drifted 1,200 km E. Ashfall was reported in Petropavlovsk-Kamchatsky. Another explosion on 14 July generated ash plumes that rose to an altitude of 2 km (6,600 ft) a.s.l. and drifted SW and 60 km S. During an overflight on 16 July, volcanologists observed fresh deposits at the foot of the volcano from collapses of the S section of Priemysh Crater (the active crater) that likely occurred on 12 July. Moderate activity at the crater continued through 19 July; the Aviation Color Code was lowered to Yellow.

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.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)