The 1977 drainage of the Austre Okstindbreen ice-dammed lake, its cause and consequences

Abstract

W. H. Theakstone 1978. The 1977 drainage of the Austre Okstindbreen ice-dammed lake, its cause and consequences. Norsk geogr. Tidsskr. Vol. 32, 159–171. Oslo. ISSN 0029-1951. In 1977, water escaping from the annually draining lake dammed by Austre Okstindbreen took a route different to that of previous years. At one point, water under pressure burst up through the glacier, fracturing its surface. The flood water eroded old moraines north of the glacier, and extensive deposition occurred on the slopes above Kjennsvatnet; the road south of the lake was breached. Drainage of the lake results from headward extension of the glacier's internal drainage system as the transient equilibrium line moves up-glacier during the summer. The seal between the system and the smaller one draining to the lake is broken as the basal water pressure gradient near the lake is reversed at a time of low discharge within the system.