KVERT reported that moderate steam-and-gas activity at Zhupanovsky continued during 5-12 February. Explosions on 5, 7, and 9 February generated ash plumes detected in satellite images that drifted over 545 km E and N. A thermal anomaly was detected during 5 and 9-11 February. An explosion at 0929 on 13 February was recorded by a video camera and generated an ash plume that rose to an altitude of 7 km (23,000 ft) a.s.l. and drifted E. A larger explosion visually observed a minute later generated an ash plume that rose to an altitude of 10 km (32,800 ft) a.s.l. and drifted 50 km SE. The Aviation Color Code was raised to Red. In a report issued at 1134, KVERT noted that only moderate amounts of gas and steam rose from the volcano; the Aviation Color Code was lowered to Orange. Ash from the earlier explosions drifted E over Kronotsky Bay and NW. A few hours later an ash plume was detected in satellite images rising 1 km above the volcano and drifting 288 km E.

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)