Bottom scour observed under Hurricane Ivan

摘要

Observations that extensive bottom scour along the outer continental shelf under Hurricane Ivan resulted in the displacement of more than 100 million cubic meters of sediment from a 35 x 15 km region directly under the storm's path are presented. Sediment resuspension was accomplished by the extreme waves generated by Ivan and transported by strong near-bottom wind-driven currents. The sediment transport was primarily westward along the shelf, but also contained a significant offshore component, suggesting sediment was transported toward the Mississippi Delta and that it may have accumulated near the shelf break and on the upper continental slope. The maximum observed scour of about 32 and 36 cm took place at two locations approximately 17 km apart along the 60 m isobath over which the maximum wind stress occurred.