Sediment Resuspension and Transport: Notes from the Tripod Program
Barry M. Lesht, Environmental Research Division, Argonne National Laboratory
- Determine threshold criteria for initiation of resuspension of the bottom sediments in the Lake Michigan coastal region associated with episodic events,
- Estimate the magnitude and direction of the horizontal near-bottom sediment flux during episodic transport events.
- An instrumented tripod was deployed at several locations in the southern basin of the lake to make long time-series observations of physical and sedimentological conditions within the benthic boundary layer.
- Tripod measurements include horizontal current velocity, water temperature (2 levels), wave height and period, suspended sediment concentration (2 levels, inferred from beam attenuation), and bottom configuration (digital photography).
- Spring transport events result from surface-wave induced resuspension of local sediments.
- Resuspension events are not limited to the spring, but occur throughout the year whenever wave conditions exceed critical threshold.
- Horizontal near-bottom sediment flux during events can approach 100 kg/m2/day.
- Simple resuspension models using wave orbital velocity as forcing can simulate events with good accuracy.
- See also Detailed Results (MS Word, 34pp, 475 K).
Summary of Argonne EEGLE Tripod Deployments
|98-1||Wind Point, WI||15m||04/02/98-04/30/98||669.5||4|
|98-2||Oak Creek, WI||25m||07/23/98-08/24/98||770.5||0|
|98-3||Oak Creek, WI||25m||10/28/98-12/01/98||815.5||2|
|99-1||St. Joseph, MI||20m||02/25/99-04/19/99||0.0||-|
|99-2||St. Joseph, MI||20m||04/20/99-06/01/99||1032.0||1|
|99-3||South Haven, MI||18m||10/15/99-11/17/99||787.5||5|
|00-4||Muskegon, MI||25m||09/12/00-present|| || |
Hawley (additional tripod measurements), Edgington, Klump, and Waples (sediment characterization), Eadie (trap analysis), and Schwab and Beletsky (transport modeling).