Making Waves
Professor�s research investigates the ocean�s effects on coastal communities
Diane Foster, assistant professor of civil and environmental engineering and geodetic science, developed this wave tank as an interactive display for COSI, Columbus� Center of Science and Industry. Visitors can pull a lever beside the tank to make waves of different length, height, frequency and celerity and observe how the beach is affected.
Diane Foster grins when people ask her what she does for a living.
�I get paid to go to the beach,� she tells them.
In all seriousness, she�s not simply sitting by the surf and basking in the rays.
Foster, an assistant professor of civil and environmental engineering and geodetic science, is a coastal engineer. In short, she studies how sand grains move on the seabed.
The longer version: Pairing field and laboratory observations with numerical models, she and her students explore the dynamics of flow and sediment transport. Their research findings are used to help predict the erosion of beaches; the scour around sub-marine objects such as pipelines, mines and bridge piers; and the re-suspension of contaminated sediments into bodies of water.
�Fundamentally, I hope to help improve our understanding of how beaches change in response to storm events,� Foster explains.
Some of her results are being used to help the U.S. Geological Survey improve its study of shelf circulation, such as what happens at the seabed level in Massachusetts Bay. In addition, she worked with student Doug Dusini, who completed his bachelor�s degree in 2001 and master�s in 2005, to study how potentially contaminated sediment can become re-suspended when lake levels are lowered.
Last summer, Foster and a group of students conducted research at the Hinsdale Wave Research Laboratory at Oregon State University, where they made use of a 342-foot-long and 12-foot-wide wave tank capable of generating waves more than 5 feet tall in 11� feet of water over 1,000 cubic yards of sand.
�We obtained some new observations about how vortices are generated and shed from ripples,� Foster says of the project, which was funded by the National Science Foundation. �We were also surprised to see how quickly the seabed responds to changing wave climates. Within just a few seconds, the seabed can evolve from rippled to flat. These observations will have a significant impact on how we model the evolution of waves and transport of sediment in coastal environments.
�These kinds of studies are important to increasing our understanding of how beaches change and erode over time, how climate change will affect beaches, and what happens when we build coastal structures.�
The Oregon trip, part of a four-year Cross-Shore Sediment Transport Experiment under way at seven institutions including Ohio State, enabled Foster�s students to see how theories they learned in the classroom and in Foster�s Coastal Sediment Transport Lab on campus translate to the sand and water in the wave tank. In addition, they met other leading oceanographers from Oregon State University, University of Florida, University of Delaware, Woods Hole Oceanographic Institution, Naval Post Graduate School and Cornell University.
�It was a collaborative experiment,� says Claire Nichols, who finished her bachelor�s degree in civil and environmental engineering and is now working on her master�s degree. �It was really neat to meet people I had been citing in my papers.�
�This whole experience taught me how to learn and how to appreciate the unknown,� says Nichols. She is considering a career in coastal engineering after she finishes her master�s degree. �It�s taught me how to see an experiment, how to conduct an experiment. For every question you try to answer, you come up with three more questions.�
Foster�s efforts to encourage interest in science and the environment extend beyond the students in her classroom. She�s building a portable wave tank to use as a teaching tool for use in local communities, and she has brought middle-school aged Girl Scouts to the College of Engineering to build Lego structures and test their strength in the wave flume she uses in her campus lab.
This year, Foster coordinated a project with COSI, Columbus� Center of Science and Industry, and the Nationwide Foundation to build a wave tank for the center�s �Ocean� exhibit. The tank, which is 14 feet long, 12 inches wide and 12 inches deep, holds approximately 120 gallons of water and 3.5 cubic feet of sand. Visitors can pull a lever beside the tank to make waves of different length, height, frequency and celerity and observe how the sand particles beneath the water are affected.
One of Foster�s graduate students, Heather Smith of Akron, Ohio, enjoys watching her research in action at the COSI exhibit, but she�s also excited about the value it brings to children.
�You get to show kids how these ripples form in the sand, so when they go to the beach, they can put their feet in the water and feel how the sand is formed,� she says. Foster says scientists and engineers must always work harder to find ways to help the public understand how and why their research benefits society.
�This is particularly true with children,� she says. �The more we can do to excite tomorrow�s scientists about performing research, the better equipped they will be to address tomorrow�s questions.�
It�s even important for adults, she adds, to learn how hurricanes, tsunamis, and sea level rise can affect our coastal communities, as evidenced by recent catastrophes like Hurricane Katrina and the Indian Ocean tsunami.
�With 50 percent of the U.S. population living within 50 miles of a coastline � and �coastline� includes the Great Lakes � problems like this will only become more significant,� Foster says. �Our efforts with COSI are a step at transitioning our fundamental research on coastal sediment transport to the public. Beyond that, it�s just fun to make waves and beaches dance.�
Contact:
Diane Foster, (614) 292-6420, foster.316@osu.edu
Visit the Coastal Sediment Transport Lab online at
http://cumin.ceegs.ohio-state.edu.
