Rip Current Mapping and Minigrid Surveys


Investigators

Kent K. Hathaway, Michael W. Leffler, William A. Birkemeier

Funding Source

Field Research Facility Analysis Work Unit,

US Army Corps of Engineers, Coastal Research and Development Program

Objective

Rip currents are strong highly localized currents that flow seaward of the surf zone and are commonly observed with regular (periodic) longshore spacing. While many investigators have considered the rip current phenomena, there are little field data about rip currents due to their elusive nature. The objective of this study will be to investigate rip current formation and spacing, and their relation to nearshore hydrodynamics and morphodynamics. A subsequent objective will be to monitor changes in nearshore morphology.

Approach

The vertical structure of the horizontal currents will be measured in and around rip currents using an instrumented sled (5 or more EM current meters and pressure gage). The presence of rip currents will be identified visually by time-averaged video imaging and occasional dye or drogue drops into the surf zone.

The second effort will be daily minigrid bathymetry surveys with the CRAB. These will consist of 26 cross shore transects (350 m long) spanning approximately 600 m in the longshore direction (700 to 1300 m in FRF longshore coordinates). This effort will be essential for many of the investigations.

For a list of addresses of the investigators involved in Duck 94 click here.