July 31, 2025
Tucked high in Canada’s remote Yukon Territory, a seismic threat that’s been quietly building for thousands of years may finally be waking up—and scientists say it could spell serious trouble for the 1,600 residents of Dawson City and surrounding communities.
According to a new study published in Geophysical Research Letters, the Tintina Fault—a massive 1,000-kilometer (620-mile) geological fracture that stretches from the Yukon into Alaska—has been quietly accumulating strain for millennia. Now, researchers believe it’s nearing the end of a seismic cycle that could trigger an earthquake exceeding magnitude 7.5.
“For decades, we’ve seen only minor quakes along the Tintina, nothing that screamed danger,” said Theron Finley, lead author of the study and a recent PhD graduate from the University of Victoria. “But when you dig into the geological record, it paints a much more alarming picture.”
Using lidar and high-resolution imaging from drones, satellites, and aircraft, Finley and his team examined a 130-kilometer segment of the fault near Dawson City. What they found were clear signs of powerful seismic events in the region’s recent geological past—massive fault scarps and ground displacements from earthquakes dating back as far as 2.6 million years and as recently as 132,000 years ago.
One scarp showed the earth had shifted by a staggering 1,000 meters (3,280 feet) across multiple quakes. Another had been displaced by 75 meters (250 feet). But in the last 12,000 years—the entirety of the Holocene Epoch—the fault has been eerily quiet.
That’s not comforting news. Quite the opposite, actually.
“The absence of recent quakes doesn’t mean safety,” Finley warned. “It means strain is quietly building up. We estimate up to 20 feet [6 meters] of slip has accumulated since the last major event.”
If that energy is released all at once, the result could rival some of the deadliest earthquakes in history—though the Yukon’s sparse population makes widespread casualties less likely than in places like Haiti or China. Still, the infrastructure damage, landslides, and loss of life could be significant.
The researchers’ models suggest the region is in a late stage of seismic strain accumulation. That means the clock is ticking, though no one can say exactly when the fault will rupture.
“All we can do is keep studying, keep monitoring, and help people prepare,” said Finley. “The Earth will move when it wants to—we just need to be ready.”
For now, Dawson City sits quietly in the shadow of a fault line that has waited 12,000 years to move again. The only question is when.
