Measuring the shake, rattle and roll in Canada’s Western Arctic

Travelling and working in remote regions of Canada’s North is no easy task. Ask Natural Resources Canada seismologist Andrew Schaeffer, who ventured to the Northwest Territories (NWT) this summer to better understand earthquakes and related natural hazards.

 

 

“I’ve travelled to this region for five years, and it’s striking how much of a challenge it is just to get here,” says Andrew. “It’s a stunningly beautiful landscape, but I find it shocking to see how much it has changed over this short time.”

Recording tiny movements to get a big picture

Andrew and a small team travelled north to monitor four existing seismometers and install a new seismic instrument in Tuktoyaktuk. Each station records tiny ground vibrations, which can be used to learn about reoccurrence, magnitude and locations of earthquakes, as well as the structure of the ground underneath. The new unit is located closer to the Mackenzie Delta and Beaufort Sea than existing stations, allowing greater sensitivity to earthquakes on the nearby shoreline.

The Western Canadian Arctic is a region of elevated seismic risk due to a relatively large number of earthquakes. However, because it’s so isolated and the work conditions are so demanding, there are few seismic instruments in the area. This makes it difficult for scientists to get a complete picture of the true number, type and magnitude of earthquakes that could occur.

Rapidly changing landscape

“It’s a challenging part of the country to work in, but it’s critical to study and improve our regional understanding of earthquakes here,” says Andrew. “The area is rapidly changing due to the effects of climate change, sea ice cover continues to shrink, the permafrost is melting, and there’s evidence of coastal erosion. With these conditions, an earthquake has the potential to cause relatively more damage than a similar one in the past.” For instance, a relatively small shake could in turn further weaken the underlying land structure and contribute to an ongoing cycle of coastal collapse and shrinking shoreline.

Areas of special interest

 

 

Coastal areas with melting permafrost are of special interest as soft, unconsolidated soils can experience far greater local ground shaking during an earthquake than frozen tundra. This instability, in part, can contribute to even more coastal collapse. Furthermore, offshore earthquakes in the Mackenzie Delta and Beaufort Sea present potential tsunami risks, which would further exacerbate already rapid coastal erosion.

With the additional station installed in Tuktoyaktuk, scientists will be able to learn more about seismic activity in the North and get better estimates of potential hazards in the area.