After 215 bodies were found at the site of a former residential school in Kamloops, B.C. last month, Canadians continue to mourn their deaths and the other who never returned home.

As shock turns to anger, calls to action are surfacing and community members are calling on leaders to search all residential school sites across the country.

“Sadly, we know this is not the only unmarked grave at one of 139 residential schools in Canada,” Dene Nation national Chief, Norman Yakeleya said on June 2.

“The families are still waiting for their children to come home. Enough is enough and the Federal Government and Churches must come clean as we walk the path of reconciliation. It is time we say the children’s’ names and bring them home.”

So how, the question becomes, can the territory act on the call.

In a sitting of the legislative assembly on May 31, Katrina Nokleby, MLA for Great Slave and former geological engineer, noted the technology used to uncover the unmarked grave in Kamloops is the same as the machinery used to measure ice thickness in the NWT.

Patrick Finlay is a senior geophysicist at Tetra Tech Canada Inc. – a global consulting and engineering firm.

He explained that with the right tools for accuracy, ground penetrating radar (GPR) works for archeology in addition to the ice profiling — its current use by the territory.

Finlay describes the technology as looking like a small suitcase dragging along the ground.

It works by emitting an electromagnetic pulse, he explained. When the pulse reflects off of the ground, the GPR is measuring the radar pulse that comes back and builds a cross section through a series of reflected pulses in the area it’s measuring. From those recordings, experts convert the data into depth measurements using the radar velocity of the material being scanned – ice for example, has a different velocity than soil or water.

To measure ice thickness for the ice roads, Finlay said the GPR frequency is typically around 500 megahertz, comparable to what would be needed to survey the soil. A key difference, he explained, is positioning.

In ice profiling, geoscientists are working with a much larger space compared to searching possible grave sites where accuracy is paramount. For this kind of work, he said GPS to collect reference data would be necessary in order to accurately map exactly where items, in this case remains, are found.

Between collecting the data and producing deliverables, Finlay said takes two to three weeks. He notes putting together the cross sections and the maps as being most time-consuming though “you can usually get a sense of what you’re seeing right away,” he said.

While the technology is mostly transferable from ice to land, Finlay said GPS doesn’t work well in fine grain soils like clay for example. That means that surveyors might have to look to alternative methods to record data around the Mackenzie Delta region.

The biggest challenge of surveying for additional grave sites, Finlay suspects, is not the data collection but rather the communication process. He emphasized the importance of keeping community members in the loop as projects move forward in addition to the ongoing communication between geophysicists specializing in GPR and archaeologists with expertise in positioning.

“I don’t think it would be very hard to come up with some sort of guideline that can be set up so that communities can look at what’s being done,” he said.

“That way the data is collected in some sort of standardized way and records are kept and documented in a way that others can access it.”

He said the planning stage would be critical to decide where exactly the surveying will take place, how the data will be documented and who is the audience.

He cautioned against “rushing into it,” and “spending a bunch of money collecting data that won’t benefit anyone.”

Natalie Pressman

Reporting courts and cops and general news, Natalie started with NNSL Media in 2020. Before moving to Yellowknife, Natalie worked as a community radio trainer in Iskatewizaagegan #39 Independent First...

Leave a comment

Your email address will not be published.