Rock On

Professor's research uncovers new local fault line data.

After an earthquake struck a nearby Virginia town a year ago, Tatiana Gilstrap made a name for herself—and Randolph College—when she became the local media’s go-to expert on earthquakes.

Tatiana GilstrapBut earth-shaking events are not the only things that pique the interest of Gilstrap, an environmental science professor. A few years ago, a retired geologist named James Keane called her with a question: Could she help him map underground basalt in the midst of acres of granite?

Gilstrap accepted the challenge. “That’s just what we scientists do. I personally thought it was really interesting,” she said.

Science first caught Gilstrap’s attention when she was in ninth grade in her native Bulgaria. Despite struggling with a demanding physics class, she realized she enjoyed the problems. “It was like trying a new dish and discovering that it was your favorite one,” she said.

Gilstrap moved to the United States in 2000 and has taught environmental science and physics at Randolph since 2006. That year, she and Keane, who teaches at both Lynchburg College and Randolph College, began researching and mapping basalt—an impermeable rock that could act like a dam for the groundwater—at Lynchburg College’s nature center.

Because basalt tends to be magnetic, the research team measured the magnetic field in 3,000 locations throughout the area to help determine where the rock lay beneath the surface. They mapped several underground dikes that probably formed 200 million years ago when the continents separated, tearing parts of the earth’s crust and allowing hot lava to flow in.

Their work resulted in geological data that prompted the team to publish a paper in Environmental Earth Sciences last fall.

But like a true scientist, Gilstrap was not satisfied with their initial research. Her data showed strong magnetic readings along a river that flows over a fault line on the property, and she wanted to discover more about the fault. This spring, she returned with Keane and her students, Mimi Joshi ’14 and Courtney Collier ’13, determined to capture an image of the fault line with a Ground Penetrating Radar machine.

 

Tatiana Gilstrap

Standing knee-deep in the cold, rushing water, Gilstrap struggled with a raft that carried Joshi as she monitored the team’s equipment. Midway across the river, Joshi called out in surprise as the radar revealed a perfect reflection of the Rockfish Valley Fault, which runs below the river. Gilstrap rushed to her side, threw up her hands in triumph, and grinned.

“This is how science works,” she said later. “As new data is gathered, we revise our previous findings and improve our understanding of the how the world around us works.”