The Eruptions of the Northern Group of Volcanoes on Kamchatka in 1988-1989: Seismological and Geodesic Data

Abstract

The results of observations of the seismic regime and deformations of the Northern group of volcanoes—Klyuchevskoy, Bezymyanny and Shiveluch—1988-1989 are reported. On Klyuchevskoy against the background of the continuing explosive-effusive eruption of the summit crater, intensive fissuring of the volcanic structure was observed in the sector between the north-eastern and southern slopes from a height of 2000 m to the summit of the volcano. Two flank eruptions at heights of close to 4000 m produced an outflow of 0.03 km' of lava each. On Bezymyanny an effusive eruption that had lasted from January 1987 ended in March 1988. A further explosive-effusive eruption took place on 2-3 August 1989. Both eruptions were very similar to the eruptions of recent years. On Shiveluch the number of explosive eruptions increased and the formation of a crater cone covering the central and western parts of the active dome was observed.