Air pockets and water lenses in the ice cover of the Slave River

Abstract

Communities along the Slave River are concerned about changes in the river ice cover, such as the formation of air pockets and double layers of ice in the ice cover. These anomalies make it challenging to find suitable locations for river ice crossings in winter, necessary for the transportation of goods to and from remote regions and to access hunting, trapping and fishing areas. This study utilized satellite imagery and field observations to document these anomalies of the river ice during the winters from November 2013 to March 2016. Backscatter analysis of the satellite imagery identified low and high density areas of air pockets along the river. Satellite images also revealed cracks and flooding of the river ice, particularly along the downstream reach of the river.