Изменчивость современных ледников вулканических районов Камчатки

Abstract

Variability of glaciers situated in volcanic regions of Kamchatka is considered. Glacier fluctuations, induced by climatic changes and volcanic activity are distinguished. Kozelsky Glacier advanced in 1971-1976. For five years it made a 330-meter advance and its area increased by 0.09 km . The advance was stimulated by favourable climatic conditions: big snowness of winters and cold summer ablation seasons. The Bil'chenok Glacier advanced in 1976-1977 after a 17-year quiescence period. The glacier terminus descended down to 1100 m a.s.l. and made a 500-m advance. The impact of present-day volcanism on glacier fluctuations was revealed: 1) glacier surges resulting from considerable water film at the glacier-bed boundary, accumulation ofadditional volumes of eruptive material on its surface and also due to the growth of seismic activity; 2) shrinkage of the area and volume of glaciers -because of ice melting and washout of their parts by melt waters under thermal influence of erupting volcano and, in particular, in case of subglacial eruptions and ice contacts with lava flows; 3) destruction of ice and glaciers by catastrophic explosive eruptions and also in case of partial subsidence and stopong of volcanoes. Some examples of the impacts of volcanic eruptions on glaciers are given.