KVERT reported that moderate activity at Zhupanovsky continued during 18-25 March. According to KVERT, the Tokyo VAAC noted that an explosion generated an ash plume that rose to an altitude of 8 km (26,200 ft) a.s.l. at 0120 on 25 March. An 8 x 10 km ash cloud observed in satellite images drifted about 135 km NW at altitudes of 3.5-4 km (11,500-13,100 ft) a.s.l. that same day. The Aviation Color Code remained at Orange.

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)