ABSTRACT

The predominantly longshore near-bottom currents in 10 m of water off the southwest Louisiana coast exhibited seasonal variability. Currents in winter were primarily westward, although easterly currents were generated rapidly by cold-front passages. Velocities increased during the spring, and the current motion was to the south-southwest as stratification developed and mechanisms other than the wind became active in the shallow waters. The summer current regime was characterized by slow, easterly motion in response to generally west and southwest winds.

Sediments were entrained by wave action and bottom currents during transient wind events, such as summer storms, winter cold-front passages, and persistent southeasterly wind events during the spring. The summer storm and spring wind events transported sediments to the west at a rate of approximately 30 km/day. Sediments suspended in early winter were moved east and west by bottom currents, but little net transport occurred. Frontal passages in March and early April transported suspended sediments more than 250 km to the west.