A major slope collapse in frozen sediments in Canada highlights the role of progressive failure.
Back in January of this year, I posted fascinating a piece by Derek Cronmiller of the Yukon Geological Survey about the 17 December 2024 Takhini River landslide and river-ice tsunami, which occurred in Whitehorse, Yukon, Canada. The location of this landslide is at [60.8611, -135.4180]. As a reminder, this is a figure from his post showing the landslide:-
Derek has now published a more detailed article in the journal Landslides (Cronmiller 2025) that provides the definitive description of this event. One element of the article caught my attention. The piece examines in some detail the initiation of the landslide. Cronmiller (2025) observes that:-
“In the case of the 17 December 2024 Takhini landslide, all common triggers are conspicuously absent, and the timing appears to be random.”
The article concludes (rightly in all probability) that the initiating mechanism was progressive failure – i.e. that the slope underwent brittle failure through a tertiary creep mechanism. Under these circumstances no external trigger is needed.
As such, Cronmiller (2025) is much more than a simple (although fascinating) case study. As Derek writes:
“While progressive failure mechanisms are commonly discussed in rockslide and gravitational slope deformation literature, their role in producing landslides in surficial sediments is discussed relatively infrequently as acute triggers commonly mask the effect of this phenomenon’s contribution to slope failure. This case study provides an important example to show that acute triggers are unnecessary to produce landslides in dry brittle surficial sediments.”
I wholeheartedly agree.
Reference
Cronmiller, D. 2025 The 17 December 2024 Takhini River landslide and river-ice tsunami, Whitehorse, Yukon, Canada. Landslides. https://doi.org/10.1007/s10346-025-02622-8
Text © 2023. The authors. CC BY-NC-ND 3.0
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