Kliuchevskoi's summit eruption continued in November and December. Lava flows reached 1.5 km in length. Gas and ash columns rose 2-4 km above the summit and bombs reached 300 m height. At times lava fountains were observed above the crater rim. Eruption character remained constant through mid-January.

Thermal infrared images from the NOAA 6 polar orbiting satellite on 23 November (at 1852) and 24 November (at 0839) showed narrow plumes emerging from Kliuchevskoi and extending roughly 60 km E. Soviet volcanologists reported that the ash column rose to about 4 km above the crater 23-24 November.

Further Reference. Gordeev, E.I., Mel'nikov, Yu.Yu., Sinitsin, V.I., and Chebrov, V.N., 1986, Volcanic tremor of Kliuchevskoi volcano (eruption of summit crater in 1984): Volcanology and Seismology, no. 5, p. 39-53.

Geological Summary. Klyuchevskoy is the highest and most active volcano on the Kamchatka Peninsula. Since its origin about 6,000 years ago, this symmetrical, basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. It rises above a saddle NE of Kamen volcano and lies SE of the broad Ushkovsky massif. More than 100 flank eruptions have occurred during approximately the past 3,000 years, with most lateral craters and cones occurring along radial fissures between the unconfined NE-to-SE flanks of the conical volcano between 500 and 3,600 m elevation. Eruptions recorded since the late 17th century have resulted in frequent changes to the morphology of the 700-m-wide summit crater. These eruptions over the past 400 years have originated primarily from the summit crater, but have also included numerous major explosive and effusive eruptions from flank craters.

Information Contacts: B. Ivanov, IVP; M. Matson and W. Gould, NOAA.