On Wednesday, October 5, Calvin senior Rob Vink will share the results of his summer research on a venerable Michigan sand dune with the people who know it best.

That day, Vink, an environmental geology major, will release his findings about Mt. Pisgah, a popular Holland tourist attraction, at the monthly meeting (4-6 p.m.) of the Ottawa County Parks and Recreation Commission. Vink will follow that presentation with a public talk on the same subject at 7 p.m. on Oct. 25 at Holland's Herrick District Library.

Of his summer job Vink says simply: "A coastal dune makes for an incredible office."

Mt. Pisgah, a large parabolic sand dune (a dune blown into a crescent shape by the wind) is located adjacent to Holland State Park, at 1.5 million visitors, the most frequented state park in Michigan. In recent years, however, the dune's popularity has raised concerns about erosion.

"Local residents have been saying that the dune is not as high as it used to be because of all the people visiting it," says Deanna van Dijk, the Calvin professor of geology, geography and environmental studies who directed Vink's research. "This summer, Ottawa County gave me a $5,000 grant to study the current status and historical activity of the dune, with a focus on human impacts."

Vink's research work validates those concerns.

He found, among other things, that Mt. Pisgah, commonly reported to be 185 feet tall is actually significantly shorter than that.

"Our ground survey work shows that Mt.Pisgah is 157 feet above Lake Michigan and 128 feet from its lowest to highest point," Vink says. "We are not sure where the 185-foot measurement is from. This could be from years and years ago, and no one has bothered to study it until now."

Vink also found that the dune has lost its characteristic pointed shape and settled into a saddle formation. These changes in the dune are only partly attributable to wind erosion.

"Natural movement of wind-blown sand has been accelerated by the presence of humans," Vink says. He estimates that more than 3,200 visitors, 90 percent of whom are not from the local area, climb Mt. Pisgah each year. The impact of these visitors are felt not only on the dune's shape, but its vegetation, which begins to degrade with 20-50 "passes" or visits a year and is destroyed by 2,000 passes.

Vink and his assistant, Calvin junior Melinda Campbell, mapped the dune's topography and surface characteristics using an electronic total station and mapping software. Vink also collected historical photographs and personal accounts from local residents to reconstruct the history of the dune and its surroundings. And he developed and administered two questionnaires about the dune to local residents and dune visitors.

"The people living in Ottawa Beach were some of the most hospitable people I have ever met," Vink says, "though I did get some ribbing from the Hope alums."

Says van Dijk: "Rob did an impressive amount of work in one summer. This project used a number of different methods to study the dune, so Rob used state-of-the-art equipment to survey and map the dune. He put a lot of time and energy into his work, including giving up some evening and weekend time to administer questionnaires to dune visitors."

Vink credited part of his success with the project to Campbell's contribution.

"The ground survey work on my study was a large undertaking and would not have happened if Melinda hadn't been out there day after day to help get it done," he says.

Campbell will present her research on dunes at P.J. Hoffmaster State Park (research gained with Vink's assistance) in mid-October at the annual meeting of the Geological Society of America, to be held Oct.16–19 in Salt Lake City, Utah.

Vink says he enjoyed his summer on the sand.

"It was definitely a great experience to be able to interact with people," he says, "and to explore the dune."