From 1995 through 1999, annual field programs were undertaken to quantify ice gouge and strudel scour characteristics for the design of the Northstar Development subsea pipelines. The main components of the field programs consisted of aerial reconnaissance missions at the time of river breakup to map the locations of strudel drainage features, and summer surveys of the sea bottom to measure ice gouges and strudel scours. The following conclusions were drawn from the data acquired: (1) multi-beam sonar offers significant advantages over single-beam sonar for locating and measuring ice gouges and strudel scours; (2) ice gouge processes in the Northstar area are relatively benign, and are comparable to those in other shallow-water environments of the Alaskan Beaufort Sea; (3) both ice gouge and strudel scour activity in the Northstar area are subject to significant inter-annual variations.
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