Ice breakup and jamming observations along the Mackenzie River

Abstract

The breakup of ice along the Mackenzie River between Fort Simpson and Fort Good Hope was studied in 1979, 1980, 1981, and 1982. This paper describes the 1980 and 1981 observations. An aircraft dedicated to this task was used to make over 40 observation flights during those two breakup seasons in which more than 20 major ice jams were observed during their formation, stationary position, and breakup. Although the paper is based on experience gained during only 4 years, it was found that all observed jams displayed the same major characteristics; hence it appears that general descriptions of ice melting, breakup, and jamming for the section of the Mackenzie River under investigation are possible. Although there could be additional variations, these are expected to be minor.The paper describes the ice melting process prior to any ice movement. The ice jamming process as it takes place along the Mackenzie River is discussed as well as the various parameters that affect this process. Several secondary factors that influence the detailed character of the jams are also addressed.