Duke University Marine Laboratory, Beaufort, North Carolina 28516, U.S.A.
Side-scan targets in Lake Superior—evidence for bedforms and sediment transport
Article first published online: 14 JUN 2006
Volume 31, Issue 3, pages 311–333, June 1984
How to Cite
FLOOD, R. D. and JOHNSON, T. C. (1984), Side-scan targets in Lake Superior—evidence for bedforms and sediment transport. Sedimentology, 31: 311–333. doi: 10.1111/j.1365-3091.1984.tb00862.x
- Issue published online: 14 JUN 2006
- Article first published online: 14 JUN 2006
- (Manuscript received 17 December 1982; revision received 5 September 1983)
A high-resolution side-scan sonar survey of the lake bed off the Keweenaw Peninsula, Lake Superior, demonstrates that bottom currents are affecting lake bed morphology at depths up to 240 m. Numerous lineations which run parallel to the shore appear to be sand ribbons. A field of sedimentary furrows which occurs in one area demonstrates the long-term directional stability of the near-bottom flow. Large (100–300 m in diameter, 2–5 m deep), unusual ring-like or arcuate depressions are common throughout the western half of Lake Superior. These rings themselves do not appear to have been formed by bottom currents, but may have developed as water was released by the rapid compaction of glacial sediments which underlie the lake bed. Off the Keweenaw Peninsula the forms of the rings have been modified by bottom currents. The bottom currents which have modified the lake bed are probably generated when storms cross the lake at times when it is poorly stratified.