Underground resources surface

Pete Yee

DIGGING FOR THE TRUTH Schmitt sits atop his seismic wave emitting truck.

Little-known subterranean landforms in the northern hemisphere and their potential uses and risks are the focus of a recent study put out by a geophysics group from the University of Alberta.

The group, headed by the Canada Research Chair in rock physics, Doug Schmitt, cooperated with the Geological Survey of Canada and the Alberta Geological Survey in putting together the research.

“People have known about the landforms for a long time and they’ve been getting water and gas out of them,” Schmitt explained. “These landforms are usually hard to find on the surface [and] they’re still not mapped out that well.”

Besides providing for water and gas, these landforms are sources of aggregate which is used in the manufacture of concrete.

The landforms that Schmitt’s group work with are glacial deposits of sediments and porous materials that are left over from progressive glaciations over the course of several ice ages. Sometimes these layers of porous material become trapped between harder, less permeable layers of rock, becoming great natural reservoirs for resources such as natural gas and groundwater.

In particular, Schmitt and his group focused on a location about 10 hours north of Edmonton, around Rainbow Lake.

“They knew [the landform] was there and it was mapped on the basis of water wells and oil wells. They knew the hole was there, but they didn’t know anything else about it. Part of the study is just trying to understand these zones and their internal structure.”

In places like Denmark, such landforms are well described by land surveys. In Canada, however, the situation is different.

“In Europe, they have smaller countries and they put a lot more effort into mapping these things out. Canada is such a vast land mass and to do it in detail everywhere would cost billions and billions of dollars,” Schmitt said. “We need to use less expensive methods to get the general picture and then if you want to go into detail a certain area of the subsurface, you can.”

However, Schmitt mentioned that such methods are never exact and serve to make surveying such landforms in Alberta more efficient.

“You never know for sure,” he said of mapping the landforms. “But you can find these zones of higher probability.”

Schmitt believes a lack of understanding of these landforms means that Alberta — and Canada — are potentially putting future sources of gas and water at risk. Schmitt believes such research bodes well for future resource management in Alberta.

“In the last decade [Alberta has been] more particularly worried about things like water. [These landforms] act as really good aquifers for water, and Alberta’s going to be short of water,” he described. “Any water we can find and use is good, though it’s a case-by-case basis. Some deposits could be recharged and some of them aren’t connected to the surface and you’d end up mining the resource.”

Schmitt cites the case of the Milk River sandstone in southern Alberta as a situation where a water resource has been mined in the past.

Not knowing where these landforms are is probably dangerous, Schmitt said.

“There’s a hazard issue with these deposits: if some guys on a rig were drilling away and they haven’t put in their surface casings to seal [gas] off — then boom, they burn a rig down,” he said. “Or if people haven’t done their due diligence [...] they might put wastes on top of these [landforms].”

Acting as aquifers, Schmitt believes that water contained in such deposits may become contaminated not just locally but in a widespread manner, since pollution can spread readily through the porous medium.

Schmitt believes that in order to best use these landforms, the government needs to continue gathering information on them.

“The government needs to better map out where these things are,” he said. “Any place that has those kinds of zones, it’s important to understand them.”