Hands-on Lab Activity: Deep Water and Shallow Water Ocean Surface Waves
Monday 4:30pm-6:00pm Quad
Poster Session Part of Monday Poster Session
A sequence of hands-on lab activities allow students to visualize theoretical and observed ocean surface wave behavior through both a physical model (wave tank) and an analytical model (Matlab). For the analytical model, students are given Matlab code to plot wave elevation profiles and the "dispersion relation" equation that describes the expected relationship between wavelength, frequency, phase speed and water depth. Students plot the equation, holding different variables constant to explore the dependency of phase speed on depth or wavelength. They then superimpose the shallow water and deep water approximations to determine the cut-off depth/wavelength ratio for the shallow water and deep water wave regimes. For the physical model, students attempt to generate waves within both the deep and shallow water regimes in a plexiglass wave tank. Students are amazed at how well the theoretical equations predict the physical wave properties in the tank! The actual depth/wavelength ratio needed to acquire the deep- or shallow-water wave approximations is also eye-opening. Students also generate standing waves using wave reflection off the tank wall. Additional lab activities may include a mix & match from any of the following options: 1) watching the sentinel 1963 film, Waves Across the Pacific featuring Oceanography legend Walter Munk, as a guided introduction to the concept of wave energy propagation across the global oceans; 2) doing pencil-and-paper work with the dispersion relation and the deep and shallow water wave approximations; 3) going outside to observe ocean waves, estimate their period and phase speed, and compare to the dispersion relation. The authors have designed and implemented these activities in upper-level undergraduate oceanography and environmental studies courses.