This radar technology helped find the burial site of 215 children in Kamloops, B.C. — could it find others?

The mass grave of 215 children in Kamloops, B.C., was brought to light through a technology called ground-penetrating radar, a tool some hope has the potential to uncover other burial sites across the country.

While the Tk’emlups te Secwépemc First Nation has not disclosed who did the work that found the 215 children, there are a handful of experts in the country using this technology to find gravesites.

Here’s how it works.

Digital maps along with the radar that is used to evaluate the soil below are the most common tools in this kind of work, says Kisha Supernant, director of the Institute of Prairie and Indigenous Archaeology at the University of Alberta.

Her team has used these techniques on an unmarked cemetery outside a former residential school in Saskatchewan, as well as at other Indigenous burial sites.

One of the first things her team does is use sensors mounted on drones that survey the area. Notable characteristics such as depressions in the ground or changes in the vegetation can sometimes indicate burial locations, she said.

The ground-penetrating radar is then brought in. There is an antenna in a box shape about the size of a lawnmower that you drag along the ground as it shoots a signal into the earth.

Ground-penetrating radar was originally designed for geology and geophysics; it’s not like an X-ray for the ground that shows you a simple picture of what’s beneath the surface, Supernant says. Rather, it is able to detect disruptions in the soil that her team must then interpret.

“What it’s looking for is actually the pit that was dug when the grave was placed,” she says. “And if it was a coffin burial, sometimes it will reflect off of the coffin. It does not actually see the body.”

It’s a slow process — the box must be dragged in lines along the earth just 25 centimetres apart. Supernant uses a frequency best suited to detecting changes in the soil two to three metres below the surface. Then, once the team has gathered its data, it goes back and analyzes the information on a computer to see if what the radar picked up matches what you’d expect to find for a burial site.

There are a couple of other techniques that are sometimes used for graves, including magnetometry, which Supernant explains as using measuring devices to look at variations in the ground’s magnetic fields. This is useful for finding bits of metal, for example, hinges on a coffin or plaques on a gravestone.

Then there’s what’s called resistivity, where you send an electrical current through the ground and look at how easily it passes through different areas — it will move faster or slower depending on the composition of what you’re looking at.

The process is expensive, and would be especially so on a large area of land, such as a former residential school, where searchers don’t necessarily know where the graves are.

Still, the process of finding unmarked graves can be profound — and certain First Nations communities across Canada are calling for funds for such searches on a wider scale.

National Chief Perry Bellegarde of the Assembly of First Nations Monday said survivors, chiefs and community members of First Nations across the country are asking if what was done in Kamloops can be done in their communities.

Mike Cooper, the vice-president of operations at ScanPlus Locating, a Vancouver Island-based company that has specialized in finding unmarked graves using ground-penetrating radar, says it’s possible with the right government funding.

The company invested in a 34-antennae machine (a normal ground-penetrating radar machine has one or two) for the purpose of helping First Nations on the coast find unmarked graves, work Cooper called sacred and necessary. The larger machine works more efficiently because it only needs to scan in one direction, and produces more accurate 3D maps deep into the ground.

It took half a day to scan an area the size of a soccer field.

“We brought all that data back, processed it all, and then we were able to determine based on history and what the community knew the grave sites look like, to pinpoint the top of each grave,” he said. “I can’t even tell you how inspiring it was — and sacred is really the only term I can use.”

Cooper said the work resulted in new burial ceremonies and rituals for that community. He said all levels of government should provide funding to any nation that wants to perform a search of old residential school grounds using the ground-penetrating radar technology.

“It will be a long time before Canada can make amends,” he said. “But definitely this country needs to step up and account for the wrongs of the past.”

The Indian Residential Schools Crisis Line is available 24-hours a day for anyone experiencing pain or distress as a result of a residential school experience. Support is available at 1-866-925-4419

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