Topographic and Ground‐Ice Controls on Shallow Landsliding in Thawing Arctic Permafrost

Abstract

An increase in Arctic shallow landsliding is a potential consequence of climate warming. Warmer summer‐air temperatures and larger rainfall events drive heat into the active layer, melting ice and decreasing soil shear stress. Topography has the potential to exacerbate landsliding by controlling the distribution of ground ice and the movement of water in the subsurface. We demonstrate that shallow Arctic landslides initiate in zero‐order drainage basins consistent with models of shallow landsliding in non‐permafrost environments. However, the low average slopes and low concavity of Arctic hillslopes cannot create pore‐water pressures high enough to generate landsliding. Instead, two‐dimensional slope stability modeling suggests that the vertical distribution of ground‐ice distributions controls landslide susceptibility. High ground‐ice concentrations close to the potential failure plane act as a stronger control than high average ice volumes or rapid thawing. Our results demonstrate that landslide susceptibility is strongly affected by topographic controls on ground ice and hydrology.

Development of a rapid active layer detachment slide in the Fenghuoshan Mountains, Qinghai–Tibet Plateau

“…Therefore, the part of the permafrost that was thawing on September 21, 2018 had not thawed in the previous 14 years (Figure 8c). This could have resulted in a rapid increase in excess pore-water pressure 18,[54][55][56] facilitating slope failure.…”

Patterns and rates of soil movement and shallow failures across several small watersheds on the Seward Peninsula, Alaska

“…Recent work modelling slope stability of thawing permafrost hillslopes found that high concentrations of ground ice near to the potential failure plane had more influence over the slope's stability compared to high ground ice volume in general or the pace at which thawing proceeded (Mithan et al, 2021). In this model, however, the only source of excess pore-water pressures was the thawing ice lenses themselves, with no representation of upslope hydrology channelling either meltwater from upslope ice lenses or any precipitation-derived moisture.…”

“…In Arctic, sub-Arctic, and Antarctic regions, the presence of permafrost and seasonal thaw lead to a range of soil transport processes strongly influenced by the thermal dynamics of the landscape (Harris and Lewkowicz, 2000;Matsuoka, 2001;Millar, 2013). Water and sediment fluxes are also influenced by the presence of excess near-surface ground ice (Li et al, 2021;Mithan et al, 2021), and limited subsurface infiltration of surface waters due to the presence of impermeable permafrost and seasonally frozen ground (Walvoord and Kurylyk, 2016). As with non-permafrost regions, rates, mechanics, and timing of downslope soil movement on hillslopes play a fundamental role in landscape evolution (Lavé and Burbank, 2004;Roering et al, 2007), the transport and storage of soil organic carbon (Yoo et al, 2006), the delivery of sediment, carbon, and nutrients to streams (Berhe et al, 2018), and the stability of infrastructure (Hjort et al, 2022).…”

Multi‐phase‐field microporomechanics model for simulating ice‐lens growth in frozen soil

“…Figure 12 shows the formation and melting of multiple ice lenses and the evolution of the fracture phase field during the numerical freeze-thaw test. Here, we use a scaling factor of 5 while the color bar illustrated in Figure 12A represents the value of the indicator function 𝜒 𝑖 defined in Equation (11). As illustrated in Figure 13 31) although the freezing front still propagates towards the bottom.…”

“…In the United States alone, it was estimated that two billion dollars had been spent annually to repair frost damage of roads 6 . Moreover, extreme climate change over the last few decades has brought increasing attention to permafrost degradation, since unusual heat waves may cause weakening of foundations and increase the likelihood of landslides triggered by the abrupt melting of the ice lens 7–11 . Under these circumstances, both the fundamental understanding of the ice‐lens growth mechanisms and the capacity to predict and simulate the effect beyond the one‐dimensional models becomes increasingly important.…”