Archaeologist Explains Technology Used In Search For Tulsa Mass Graves

After nearly two weeks of searching for possible mass graves from the 1921 Race Massacre, the Oklahoma Archaeological Survey is analyzing the data they collected.

The team used three different pieces of equipment to gather information about what is underground.

One of the tools, the ground-penetrating radar, looks like a small lawnmower.

"We're actually collecting a reading every centimeter as we move along,” Senior Researcher Scott Hammerstedt said.

When Hammerstedt goes over the ground with the radar, he sees parabolas displayed on a screen, signifying something is underground. That data needs to be processed to learn more about it.

"So, we know what it looks like from the top, and what it looks like from the side underneath,” Hammerstedt said.

The gradiometer is another tool used by the team. It has an “H” shape to it.

"I jokingly say it looks like a tie fighter from Star Wars,” Hammerstedt said.

He said the gradiometer detects subtle magnetic anomalies in the soil. The tool is very sensitive to metal and is the reason archaeologists have to be careful about what they wear while they work.

The third piece of equipment is the electrical resistance meter, which measures the moisture in the ground.

"It basically shoots a small electrical current into the soil,” Hammerstedt said.

Even with all the technology, the archaeologists still use a pencil and notebook to take notes they can refer to when analyzing the data. 

"It helps me keep things straight. It helps me sort things out in the computer later on. And just little reminders of why I did what,” Hammerstedt said.

The archaeologists plan to be back in Tulsa in a few weeks to search one more cemetery. The city expects to release any findings by January.