Volume 39, Issue 1 (January 1994)
Drift Trajectories of a Floating Human Body Simulated in a Hydraulic Model of Puget Sound
After a young man jumped off a 221-foot (67 meters) high bridge, the drift of the body that beached 20 miles (32 km) away at Alki Point in Seattle, Washington was simulated with a hydraulic model. Simulations for the appropriate time period were performed using a small floating bead to represent the body in the hydraulic model at the University of Washington. Bead movements were videotaped and transferred to Computer Aided Drafting (AutoCAD®) charts on a personal computer. Because of strong tidal currents in the narrow passage under the bridge (The Narrows near Tacoma, WA), small changes in the time of the jump (± 30 minutes) made large differences in the distance the body traveled (30 miles; 48 km).
Hydraulic and other types of oceanographic models may be located by contacting technical experts known as physical oceanographers at local universities, and can be utilized to demonstrate trajectories of floating objects and the time required to arrive at selected locations. Potential applications for forensic death investigators include: to be able to set geographic and time limits for searches; determine potential origin of remains found floating or beached; and confirm and correlate information regarding entry into the water and sightings of remains.