Holmsjön is one of the throughflow basins of the regulated river Ljungan. The ice push in this regulated lake in the winter of 1970/71 was extremely powerful because the meteorological and hydrological conditions for thermal ice expansion were very favourable and they were correlated in time. Rapid and extensive variations in temperature occurred repeatedly, the ice was almost free from snow, stable and thick. At the same time the water stage was close to the upper storage level, and the shore material was very little frozen. The formation of ice-push ridges was especially comprehensive along the southern shore area because of the favourable geomorphological and geotechnical conditions. The shore is here formed in sandy till, the shore configuration is relatively smooth, the bottom slope is small to moderate, the opposite shore is built up of more erosion-resistant material and is situated at an optimal distance, that is 1-3 km from the southern shore.

A larger file in Swedish.

Back.