Hidden fault line could cause catastrophic earthquakes across North America: researchers

We’re on shakier ground than previously thought.

Canadian scientists have warned that an overlooked fault line could unleash catastrophic earthquakes across North America — disrupting infrastructure, triggering landslides and impacting thousands of people from Alaska to Montana.

The study, which was conducted by geologists with the University Of Victoria in British Columbia and published in the journal Geophysical Research Letters, found that this terrifying feature has been stealthily lying in wait for quite some time.

“This new study shows it has been quietly building toward a potentially very large earthquake,” Dr. Michael West, the state seismologist at Alaska Earthquake Center, told the Daily Mail. “It is one of the least studied fault systems in North America, and that needs to change.”

Dubbed the Tintina fault, the seismic structure extends more than 621 miles across the Yukon from Northeastern British Columbia into Alaska, Phys.org reported.

Despite shifting laterally nearly 280 miles in its lifetime, scientists believed that the tectonic monstrosity — which was discovered in 1912 — had remained dormant for 40 million years.

Unfortunately, it appears there was a fault in their intel.

Using topographic imaging from satellites, aircraft and drones, researchers have now uncovered an 80-mile section just 12 miles from Dawson City, Canada, that has evidence of large earthquakes during the Quaternary Period — an epoch spanning the last 2.6 million years to the present, SciTechDaily reported.

“Over the past couple of decades, there have been a few small earthquakes of magnitude 3 to 4 detected along the Tintina fault, but nothing to suggest it is capable of large ruptures,” explained Theron Finley, a recent UVic Ph.D. graduate and lead author of the recent article. “The expanding availability of high-resolution data prompted us to re-examine the fault, looking for evidence of prehistoric earthquakes in the landscape.”

They specifically discovered glacial landforms that were offset across the fault escarpment by more than 3,000 feet, 2.6 million years ago, and others that slipped over 245 feet, 135,000 years ago.

Meanwhile, the Tintina fault continues to strain at 0.2 to 0.8 millimeters annually, indicating that a major seismic event could be on the horizon.

“We determined that future earthquakes on the Tintina fault could exceed magnitude 7.5,” warned Finley. “Based on the data, we think that the fault may be at a relatively late stage of a seismic cycle, having accrued a slip deficit, or build-up of strain, of six meters in the last 12,000 years. If this were to be released, it would cause a significant earthquake.”

A tremor of this magnitude could cause severe shaking in Dawson City and threaten nearby highways and mines, as well as cause landslides in the notoriously rockfall-prone region.

Meanwhile, experts fear that the fault could trigger severe earthquakes in Alaska’s Fairbanks North Star Borough that have the potential to impact over 125,000 people as well as affect critical infrastructure such as the Trans-Alaska pipeline, the Daily Mail reported.

Some fear the tremors could affect regions as far as Montana, like something out of a Roland Emmerich disaster film.

How did such a potentially cataclysmic threat fly under the radar for so long?

Experts believe that it has to do with shaky data and our distorted timescale — seismic hazard estimates are informed by historical earthquake records, including Indigenous oral histories and info from modern seismic networks that only go back a few hundred years.

Meanwhile, the new research indicates that landforms that were 12,000 years old weren’t displaced by the fault, suggesting that there haven’t been any large ruptures since then.

“We are not good at thinking about things that happen every 12,000 years,” said West.

Not to mention that the ruptures, which can be over 100 miles long but just several feet tall, are difficult to detect in heavily forested regions like Canada without the aforementioned topographic radar tech.

“The most dangerous thing is not just that the fault is active,” said West. “It is that no one’s been paying attention to it.”

Canada’s National Seismic Hazard Model (NSHM) currently doesn’t recognize the Tintina fault as a discrete quake fault source, but plans to integrate the findings by the team in the future so they can help formulate plans to help save human lives and infrastructure.

The study will also be shared with local governments and emergency managers to help better earthquake preparedness protocols in their communities.