A long-overlooked geological fault in Canada’s remote north may have the potential to produce a massive earthquake, according to new research.
The Tintina Fault, extending about 620 miles (1,000 kilometers) from British Columbia to Alaska, was once believed inactive for at least 40 million years. Scientists now reveal it has experienced significant ruptures within the last 2.6 million years and could rupture again.
Researchers from the University of Victoria identified an 81-mile (130-km) section near Dawson City where multiple past earthquakes have reshaped the terrain. Using high-resolution topographic data from satellites, aircraft, and drones, they detected fault scarps hidden under dense forest and glacial deposits.
“Lidar and satellite data have revolutionized paleoseismology, uncovering faults previously unknown,” said lead author Theron Finley.
Measurements show glacial features 2.6 million years old have shifted about 0.62 miles (1 km), while 132,000-year-old formations are offset by 246 feet (75 meters). Features just 12,000 years old remain undisturbed, indicating a long period of inactivity.
However, this quiet phase may not be reassuring. Based on tectonic strain rates of 0.2 to 0.8 millimeters per year, the fault has likely accumulated about 20 feet (6 meters) of slip deficit since its last major quake.
The Tintina Fault is a right-lateral strike-slip fault, similar to California’s San Andreas Fault, where land masses grind past each other horizontally. This type of fault can cause sudden, powerful shifts, releasing massive energy in one event.
A rupture on this section could exceed magnitude 7.5, potentially causing severe shaking in Dawson City, damaging infrastructure, and triggering landslides. The Moosehide and Sunnydale landslides nearby already show instability.
Despite the risk, the Tintina Fault is not currently listed as a separate seismic source in Canada’s National Seismic Hazard Model. Findings from this study will be considered in future updates and shared with local authorities for improved emergency planning.
