Finding unmarked graves: Queen’s University offers free expertise to Indigenous communities

We want to know, the relatives want to know, and they have the right to know if relatives are buried there.”

Dr. Alexander Braun, Queen’s university geophysics professor
Ground penetrating radar (GPR) is one of the best tools to find unmarked graves. Photo provided by Dr. Alexander Braun

Several Queen’s University staff members have started an initiative offering free, professional expertise in finding unmarked graves to Indigenous communities across Canada.

“Let us know where you need us — equipment, software, processing time, surveyors… we will be available for any Indigenous project across Canada for free at a professional level,” said Dr. Alexander Braun, geophysics professor at Queen’s University.

A new website is currently being developed for the initiative.

Braun had led seven pro-bono cemetery surveys in the past few years, searching for and finding unmarked graves along the Rideau Canal using the same ground penetrating radar (GPR) technology utilized for the latest discoveries at residential schools.

“We did [cemetery surveys] as a community project — no funds were involved. [We did work] to better understand old cemeteries from the 1800s: cemeteries without markers, with no records where burials are located,” he said.

“We had a map of how many burials were there, what the orientations were. [It’s] part of geophysics. We did it professionally, but we didn’t charge.”

A geophysicist’s expertise usually costs a substantial amount, but Braun insists that “it’s not the right thing to do to charge money for this. We cannot get paid [for this work],” referring to the free surveys the initiative is offering.

Let us know where you need us — software, processing time, surveyors. We will be available for any Indigenous project across Canada for free at a professional level.”
Dr. Alexander Braun, Queen’s university geophysics professor

How does GPR work in uncovering graves?

Dr. Alexander Braun, Queen’s University geophysics professor
Photo by Dr. Alexander Braun.

A GPR, according to Braun, is “a transmitter, which generates radar pulses — same as microwave pulses. We take the waves and send them to the surface.”

Braun describes how it works as similar to someone sitting in the middle of the room, talking. The echo of the person’s voice bounces back from the wall, yet no one can tell for sure which wall the echo came from.

In cases of trying to find human remains underground, for example, the main limitation of a GPR is that one can “never [be] sure where this ‘reflection’ came from. We never know the exact location,” he said.

GPR is the “most suitable technique for archaeological artifacts in a shallow sub-surface,” Braun added. Its most important role is that it can sense when someone has disturbed the soil by digging, thus changing the compactness of the soil.

“If you plant a tree and you dig a pit, and you put the soil back in, you always have something left because you cannot compact it as well as nature did. It is less compact, allows it to store water longer,” Braun explained.

The pink and blue image (above right) is the distribution of headstones at the
Cataraqui Cemetery in Kingston obtained from drone footage. The image on the bottom left
is a radar-gram of a contemporary cemetery which shows the reflection
hyperbolas (dome shaped features), which indicate burials. The picture
on the right is a cemetery along the Rideau Canal where burials of miners
and sappers engineer corps are located. Graphic provided by Dr. Alexander Braun.

By principle, Braun said that one can find burial sites by looking at how robust the grass grows on the burial ground compared to its surrounding areas. However, this method only works for a few years, and certainly will not work for unmarked graves that have been left for decades.

Braun clarified that a GPR cannot show human skeletal remains.

“If you’re looking for a bone, this is too small to reflect radar waves, too small for us to pick up,” he said.

“We’d need X-rays, you can see each bone in your body — but they’re higher frequency than radar waves and can’t travel as deep. Radar waves travel further, but do not resolve small features [such as a bone]. There’s always a compromise.”

Even with its limitations, a GPR is still a very important tool in finding unmarked graves. It is the first step in confirming that there’s been a burial, in a non-invasive way.

“We never touch the ground. We roll the GPR on wheels, we just push the GPR over the grass,” Braun said.

Ground penetrating radar is a non-invasive tool in locating burial sites. Photo submitted by Dr. Alexander Braun.

Are the numbers accurate?

With the discovery of over 1,100 unmarked graves using GPR technology — 215 in Kamloops, 751 in Marieval and 182 in Cranbrook, Braun was asked how accurate a GPR machine could be.

“Those numbers are not exact. Why is that? What you get from the radar ground, you have to make a distinction: which one is a boulder, a tree root, or a burial?”

In Marieval’s discovery, for instance, Braun explained that “it is a confirmation that there have been burials. They had 751 targets identified in the sub-surface.”

The main goal was to identify burials that are unknown, and that the next step — excavating the remains — is when the exact number will be revealed.

Two experts in archaeology from Queen’s University have signed up for the initiative. “They have licenses and expertise in digging up Indigenous sites in the past. It’s much more sensitive [work] than what we [geophysicists] do,” Braun said.

Emotional Toll

When dealing with such a sensitive matter, there is an emotional impact of the work Braun and his colleagues do.

“I would say it’s quite humbling. You’re going back in time. All those people had a history, some were not good,” Braun expressed.

“We want to know, the relatives want to know, and they have the right to know if relatives are buried there. We’re doing work because someone asked us to do this, a real application for a human cause.”

We’re doing the technical work to assist in finding out the truth.”

Braun hopes that Indigenous communities will reach out and avail of his expertise — for free.

“We have the expertise. There’s not many people in Canada with this kind of expertise. You can purchase a GPR for $25,000 to $30,000, buy the software, and you can do it yourself. But geophysicists are licensed… and can interpret everything. You should have a professional licensed geophysicist overseeing those projects, it’s very important,” he said.

“We’re doing the technical work to assist in finding out the truth.”

Dr. Braun can be reached through by email at [email protected].

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