Geologists use ground-penetrating radar to assess Oxford sinkhole

Geologists used ground penetrating radar to take readings at the Oxford sinkhole on Tuesday.

It's the first test to get a better look at what's underground.

Underground specialist Philip Jennex scoured the site of the sinkhole with his ground penetrating radar to get a better look of what's under his feet.

The device sends a pulse of energy into the ground and once the machine hits a feature underground, it reflects a picture back into the machine.

“So, when it reflects, the software takes over and interprets that into an image, which comes onto the screen and you see it as you go,” said Jennex.

It's the first such piece of equipment to be used at the site and it’s a moment officials have been patiently waiting for.

“It was kind of exciting, because it's the step towards knowing more,” said Rachel Jones, Town of Oxford’s Chief Administrative Officer.“It’s more than what we've been able to do up to now, so it is exciting.”

But what lies beneath isn't always clear at first glance.

“A tree root can look the same as a pipe, or a piece of two by four can look the same as a tree root,” Jennex said. “You’re looking for features. You’re looking for things that are out of the norm for this kind of place.”

The test was strictly preliminary and Jennex says it's hard to determine the exact results this early. But he did discover some interesting features.

“That area back there is less saturated with salt than this area out here,” he said. “Which is interesting in itself. Why so much salt out here versus none back there?”

The ground penetrating radar test costs $1,500 and that's being paid for by the Town of Oxford. If they do decide it’s a worthwhile technique and want to move forward with an entire ground survey, that would cost about $36,000.

The sinkhole itself has not grown in more than a week, but geologist Amy Tizzard used purple spray paint to highlight some new cracks discovered Tuesday.

“We identified some fresh cracks in the pavement around the sinkhole and they're about four metres back from the edge,” said Tizzard, a geologist with the Nova Scotia Department of Energy and Mines. “It's a reminder that the site continues to develop.”

And as for the results from Tuesday's ground penetrating radar testing, it's now up to the town of Oxford to analyze the results. They will then consult with their councilors and the province before deciding what to do next.

With files from CTV Atlantic’s Kate Walker.