University of Saskatchewan graduate students use ground penetrating radar at the Nutana Pioneer Cemetery project in Saskatoon, Sask.Supplied
The radar penetrates into the ground and bounces back again and again, its return measured in nanoseconds that indicate disturbances in the ground below. Large rocks and loose soil. The shaft of a grave.
Working at the site of the former residential school on the Muskowekwan First Nation in Saskatchewan in 2018, Dr. Terence Clark watched the screen display on his ground-penetrating radar, noting the size of the disruptions, their shape and distance under the ground, until he could say with certainty what those in the community had known all along: There were children buried on that hill.
“What was profound to me is that when survivors talk to you, they know that children are buried here, and they point to the hill,” said Dr. Clark, a University of Saskatchewan researcher and professor who specializes in community-based archeology. “It seemed like this was a validation that their memories were real, this really happened, and they wanted to see it on the screen. They wanted to know that what they experienced was true.”
It was.
The team at Muskowekwan located 35 gravesites before the project was paused for additional government funding.
“It was shocking and sad, absolutely, for the community and the surrounding areas. We don’t know who they are,” said Muskowekwan Councillor Cynthia Desjarlais, who led the effort to bring Dr. Clark and his team to the First Nation northeast of Regina. “And there’s no markers whatsoever. No history or documents.”
The use of ground-penetrating radar, or GPR, to locate remains of children on residential school sites has been going on around the country for several years, often spearheaded by university teams such as Dr. Clark’s, as well as others from the University of Alberta, UBC, Lakehead and Simon Fraser.
These projects were already poised to expand around the country with federal funding promised in 2019, when GPR suddenly became headline news last week. On Thursday, the Tk’emlúps te Secwépemc Nation announced the technology had been used to locate 215 unmarked gravesites at the site of the former Kamloops Indian Residential School. The southern B.C. nation reported some of the remains belonged to children as young as 3.
Leadership of Tk’emlúps te Secwépemc have said the findings are preliminary, and they are not currently releasing any further details about the search or who conducted it, while they grieve, hold ceremonies and consult with leadership of other communities who had children at the school.
The work was funded by a $40,000 federal grant from the Canadian Heritage Ministry issued last year. A report about the findings is expected later this month.
How GPR works
Ground penetrating radar, or GPR, is increasingly
being seen as an effective tool to locate
unmarked gravesites, such as those believed to
be present around Canada’s residential schools.
But experts say the work requires careful meth-
odology, protocols and standards to ensure the
findings are accurate and warn that the stakes
are high.
Sites are divided into grids to ensure accurate data collection
Monitor
Operator
Antenna
Control
unit
High-
frequency
radio waves
GPR works by passing back and forth over a
gridded survey site with a portable cart-mounted
unit. The control unit emits a continuous series of
high-frequency radio waves, which pass through
the ground. The strength and rate at which this
electromagnetic energy is reflected back from
various materials is measured. Different substanc-
es have various capacities to store or reflect elec-
trical energy; metal has a high capacity to reflect
energy, while dry sand has much less. The data is
then displayed as a radargram that can be inter-
preted by experts.
Example of
a GPR cross-
sectional
radargram
JOHN SOPINSKI AND murat yükselir /THE
GLOBE AND MAIl, sources: leica; geomodel
inc. (radargram); sensors and software
inc.; groundpenetratingradar.co.uk; geo-
physical.com
How GPR works
Ground penetrating radar, or GPR, is increasingly
being seen as an effective tool to locate unmarked
gravesites, such as those believed to be present
around Canada’s residential schools. But experts say
the work requires careful methodology, protocols and
standards to ensure the findings are accurate and
warn that the stakes are high.
Sites are divided into grids to ensure accurate data collection
Monitor
Operator
Antenna
Control
unit
High-
frequency
radio waves
GPR works by passing back and forth over a gridded
survey site with a portable cart-mounted unit. The
control unit emits a continuous series of high-fre-
quency radio waves, which pass through the ground.
The strength and rate at which this electromagnetic
energy is reflected back from various materials is
measured. Different substances have various capaci-
ties to store or reflect electrical energy; metal has a
high capacity to reflect energy, while dry sand has
much less. The data is then displayed as a radargram
that can be interpreted by experts.
Example of
a GPR cross-
sectional
radargram
JOHN SOPINSKI AND murat yükselir /THE GLOBE AND
MAIl, sources: leica; geomodel inc.(radargram);
sensors and software inc.; groundpenetratingra-
dar.co.uk; geophysical.com
How GPR works
Ground penetrating radar, or GPR, is increasingly being seen as an
effective tool to locate unmarked gravesites, such as those believed
to be present around Canada’s residential schools. But experts say
the work requires careful methodology, protocols and standards to
ensure the findings are accurate and warn that the stakes are high.
Monitor
Operator
Antenna
Control
unit
High-
frequency
radio waves
Sites are divided into grids to ensure accurate data collection
GPR works by passing
back and forth over a
gridded survey site with
a portable cart-mounted
unit. The control unit
emits a continuous series
of high-frequency radio
waves, which pass
through the ground. The
strength and rate at which
this electromagnetic
energy is reflected back
from various materials is
measured. Different sub-
stances have various
capacities to store or
reflect electrical energy;
metal has a high capacity
to reflect energy, while
dry sand has much less.
The data is then displayed
as a radargram that can
be interpreted by experts.
JOHN SOPINSKI AND murat
yükselir /THE GLOBE AND
MAIl, sources: leica; geo-
model inc. (radargram);
sensors and software inc.;
groundpenetratingradar.
co.uk; geophysical.com
Example of
a GPR cross-
sectional
radargram
Dr. Kisha Supernant, director of the Institute of Prairie and Indigenous Archaeology at the University of Alberta, says evolving GPR technology is making it possible for researchers to accurately locate and identify human remains through the ground, and even to make conclusions about the ages of the deceased. But conducting the examinations, and understanding and interpreting the results, takes considerable training and expertise. Think scans that need to be read, not X-rays that show a skeleton.
“I think there has, in the past, been skepticism about the application of this particular technology to grave sites,” says Dr. Supernant, who is Métis. “But as someone who has actually done it, and done it repeatedly, with the right application of the method, with a good research design specifically designed to find graves, I would say that we can get very confident that what we’re seeing is itself a grave.”
The reality of ground-penetrating radar is both more amazing, and also less clear, than the average person might expect.
Dr. Clark describes GPR machines as toaster-sized boxes that can be pulled along with a wheel or pushed in a carriage. Initial scanning only takes about as long as it does to walk the areas being searched, and later the data are downloaded and processed by computers. He says the set-up he uses cost about $35,000.
But while disruptions in the ground indicated by the GPR may look like little more than “blobs” to the untrained eye, experienced researchers can come to recognize the look and depth of different grave shafts and distinguish grave patterns in certain locations.
For instance, Dr. Clark says researchers have learned children tend to be buried in shallower graves than adults, and that the remains on residential school properties are usually not in coffins, but wrapped in a blanket or nothing at all.
He also says it’s possible to estimate the ages of the deceased, by comparing GPR findings with historic graves where the tombstone indicates the age of the deceased.
Dr. Supernant says she has worked at six or seven sites with unmarked graves, including Muskowekwan, as well as historic cemeteries, and that when done properly, searchers are able to distinguish between other kinds of disruptions in the ground – such as a large rock – and a gravesite.
“There’s enough precision when the method is applied correctly to be able to distinguish between those things,” she said. “Now, can we ever be 100 per cent? I would say probably not. But we can get very close to 100 per cent.”
Dr. Clark says GPR findings can be further refined in combination with electronic magnetometry, which picks up disruptions in magnetic fields, and drone imagery to find disturbances in the foliage and growth in the area. He says his team is also looking into environmental technology, which could be used to detect human DNA near a gravesite without disturbing the remains.
He says the success and accuracy of the techniques have been affirmed at archeological sites around the world where, after graves are initially located using GPR techniques, human remains are unearthed.
As the demand to locate and identify unmarked gravesites on former residential school properties grows, Dr. Supernant and Dr. Clark say it’s important to ensure the work is being done by individuals and companies who are using the specific research protocols and techniques.
“Right now, I think some First Nations are approaching or being approached by companies who don’t actually have experience in using GPR to find graves, or using similar technologies to find graves,” Dr. Supernant said. “And I have serious concerns about that.”
Dr. Supernant says she hopes to see a national strategy setting standards for how the work is being done, and that First Nations not only be given money to fund the searches, but support to hire companies that will follow the practices and protocols that have been established to ensure the most accurate results. She suggests that could include a peer-review process, where work is examined by other experts before being provided to the community.
She says GPR equipment was developed for geophysical exploration such as mining, and that there is a lot of room for error if the proper research methods for gravesites aren’t used.
“There’s solid science,” she said. “And we don’t want communities to feel as though they have to exhume bodies to prove that there’s graves.”
Dr. Supernant said it’s important to minimize the chance that further harm could be caused in this process. Given the emotion and significance of the sites, mistakes would be devastating.
“There’s a lot riding on this,” she said.
On Muskowekwan, Councillor Desjarlais says elders felt the gravesites should stay undisturbed, and the community decided no remains would be intentionally unearthed. Chief Reg Bellerose said the focus right now is to mark off and protect the area. A healing garden is planned for the site.
Mr. Bellerose says locating the gravesites was painful but that it has been part of a new push toward healing in his community; construction is currently under way for a family wellness centre.
The residential school, which was one of Canada’s last, still stands. It is currently empty, but the community hopes to make it an education or archival centre one day.
“With Muskowekwan, there was a refusal of knockdown because we felt that the history would be erased,” Mr. Bellerose said.
Ms. Desjarlais says this week, many people from neighbouring communities have stopped at the school to pay their respects, and in some cases, offer their condolences for what the children suffered.
In recent days, Muskowekwan held a pipe ceremony at the site and Mr. Bellerose said he has reached out to the leadership of Tk’emlúps te Secwépemc Nation to express his support.
“The problem was not created by us. But the solution needs to be created by us,” he said. “The priests are gone, the nuns are gone. And it’s up to the community now to deal with all this stuff.”
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