Geology, From Above

Trinity geosciences professor Ben Surpless wants to study fault lines, but he doesn’t want to plunge to his death.

“People told me, ‘Oh, you should learn how to rappel,’” says Surpless of his geology exploits, “but in reality, one rope on the side of a cliff … that’s not an effective use of my time and energy, and I also don’t want to die.”

So, Surpless has decided on an innovative solution: using drones to produce 3D maps of a fault system. This method is opening a door for faster and more efficient research on gas and oil recovery, groundwater flow, geothermal energy, and even earthquakes.

Surpless, along with geology majors Caroline McKeighan ’19 and Curtis Segarra ’19, actually spent their summer collecting field data by flying drones armed with high-tech cameras across a major fault zone in south central Utah.

“With drones, you can get at data that you couldn’t possibly get at without that additional step [of climbing rocks],”, Surpless says. “This is where a lot of geologists are looking, especially ones who rely on field data that’s difficult to collect.”

Scientists have studied faults—massive cracks in the earth caused by mass rock movement —for hundreds of years, but this work has typically involved hours upon hours of sometimes dangerous field research. By using drones, Surpless says, scientists can cover much more territory.

Data from the research done by Surpless’ group, funded by the National Science Foundation and in partnership with the Keck Consortium and students from the College of Wooster (Charley Hankla ’19) and Mount Holyoke College (Madison Woodley ’19), will take time to process, but has already produced a groundbreaking new model for fault system mapping.

Drones with stabilizing cameras fly over a fault zone—which typically includes challenging topography ranging from hundred-foot cliffs and outcrops to deep ravines and gullies—taking 4K video of the geological formation from multiple angles.

The group then uses a specialized software package, Agisoft Photoscan Professional, to transform the footage into hundreds of photos with millions of specialized spatial points, creating a 3D mesh—or model—that can be laid out over a geographic area. When paired with real-world coordinates in ArcGIS software, this map can serve as a functional reference for geoscientists running numerical computer simulations of major fault systems.

“We’re not the first people to integrate Agisoft Photoscan with ArcGIS software,” Surpless says. “But I haven’t seen anyone else also run computer modeling of the system using two other pieces of software in order to better understand how fault lines evolve over time.”