Recent frost fissuring in a coastal area of southwestern Sweden

Abstract

Violent shaking of the ground accompanied by cracking sounds are reported (1966 and 1987) from a coastal area of southern Sweden. Analysis of fissure pattern and records from two nearby meteorological stations contradict the statements by newspapers that the origin was earthquakes and give clear evidences of the events being the result of an arctic frost phenomenon. The conditions for thermal contraction, low temperature, rapid cooling, ground quality, and their interaction arc discussed from observations made in the area. The recent events of occasional Assuring bring up the fossil traces (ice-wedge casts) of recurrent Assuring in a permafrost environment during cold phases in Late Weichselian time. By studying records and reports from the other Nordic countries it is concluded that the study area is the southernmost know n locality of the phenomenon in Scandinavia, situated far outside the present arctic realm. The idea is advanced of an increased frost Assuring in areas outside the Arctic as a presage of an approaching climatic deterioration.