Tintina fault (Yukon, Alaska, US and Canada) becoming more active?

[Astronuc]

Scientists Believe This Major Earthquake Fault Line Is Waking Up​

https://time.com/7306264/tintina-earthquake-fault-line-study/

High up in Canada’s Yukon Territory, a seismic gun is being cocked and aimed at the little community of Dawson City—population 1,600. If a new study in the journal Geophysical Research Letters is correct, that town or one of many others in the region could be rocked by a major earthquake pretty much at any moment. The source of the danger is a 1,000 km (620 mi.) formation known as the Tintina fault that cuts northwest across the Yukon and terminates in Alaska. It has been mostly still for the past 12,000 years but appears to be getting ready to lurch to life.



“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,” said Theron Finley, a recent PhD graduate at Canada’s University of Victoria and the lead author of the study, in a statement. That’s not the full story, though, Finley says. What the last few decades suggest and what the geological record now shows are two different things—and according to the paper, Tintina is a lot more menacing than it seems.

What caught the interest of Finley and his colleagues is a 130-km (80 mi.) segment of the fault that runs near Dawson City, with surface features suggesting that numerous large earthquakes occurred in relatively recent geological history—during the Quaternary Period, which runs from 2.6 million years ago to the present. . . .

Large Surface-Rupturing Earthquakes and a >12 kyr, Open Interseismic Interval on the Tintina Fault, Yukon​

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2025GL116050

Yukon-Charley Rivers National Preserve (Alaska, US) is one of the rare locations in North America where so much of geologic history is preserved (Precambrian era to the Cenozoic). The Yukon River meanders through the preserve for a distance of approximately 130 river miles and drops about 200 feet along its route. The Yukon River and its tributaries cut rough-hewn cliffs, exposing remarkably complete records of the floral and faunal history of Eastcentral Alaska.

https://www.nps.gov/yuch/learn/nature/geology-on-the-yukon-river.htm

The Tintina Fault divides the preserve into two distinct geologic areas. The Tintina Fault is a strike-slip fault that runs parallel to the Yukon River corridor six to twelve miles south of the river. This fault is one of the great fault systems in western North America, extending 600 miles from northeastern British Columbia into Alaska.

Northeast of the Tintina Fault, the greatest bedrock diversity occurs in a triangle formed by the Nation and Yukon Rivers and the Canadian Border. This triangular area is the only portion of Eastcentral Alaska thought to be part of the original North American plate and it comprises a sequence of unmetamorphosed sediments (Precambrian, Cambrian, Ordovician, Silurian, Devonian, and Mississippian). These sedimentary rocks were once part of a continental margin and contain an outstanding record of marine faunal evolution that includes ammonites, trilobites, brachiopods, and corals. The oldest known microfossils from northwestern North America are also found in this triangular area.

The area southwest of the Tintina Fault is a sequence of complex igneous rocks, metamorphic sedimentary rocks, and volcanic rocks. These rocks were probably metamorphosed and reformed when several small plates collided to form Alaska during the Cretaceous.

Dawson City is a city on the Yukon River in Yukon, Canada.
https://en.wikipedia.org/wiki/Dawson_City
64°03′36″N 139°25′55″W

 

[Andrew Mason]

Thanks for posting this. This article suggests the oldest formations that show no signs of having been affected by a seismic shift are about 12,000 years old. "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."

 

[256bits]

Scientists Believe This Major Earthquake Fault Line Is Waking Up

These posts of yours lead me to learn features of the geological earth that I would never have known about. Keep up the good work.