Introduction Twenty-five years ago, Arctic offshore hydrocarbon resources seemed on the verge of rapid and energetic development, but cost and technical uncertainty made the economics questionable. Today, some Arctic projects appear economically and technically feasible and are receiving renewed interest in both the North American and Russian Arctic although there are still technical questions and environmental opposition. All indications are that the industry will begin with the less ambitious and less difficult projects and apply the lessons learned to the more difficult projects. Ice Gouging Large masses of ice are pushed by ice sheets and pack ice driven by wind and currents. In the western North American Arctic and in the Arctic islands there are no true icebergs but many multiyear ridges and occasional ice islands.
True icebergs exist in the eastern Arctic.
When ice masses run aground they continue to move and can cut gouges more than 50 m wide and 5 m deep into the seabed. The most intense gouging occurs in water 20 to 30 m deep. Gouge profile interpretation is complicated by the fact that a profile is a dynamically changing picture influenced by gouge infill produced by repeated gouging and by normal seabed-sediment transport caused by waves and currents. Burying the pipeline below gouge depth is not sufficient for pipeline protection because intense deformation occurs beneath a gouge and the pipeline can be damaged by being dragged with the seabed soil below a gouging ice mass. Three damage zones can be identified.