Permafrost thaw‐related slope failures in Alaska’s Arctic National Parks, c. 1980–2019

Abstract

Active‐layer detachments (ALD) and retrogressive thaw slumps (RTS) are landslides that occur as a result of thaw in permafrost regions. I mapped the extent of bare soil exposed in these thaw‐related slope failures in four study areas with continuous permafrost in Alaska’s Arctic National Parks, on mosaics of aerial photographs from 1977–1985 (sampling episode 1), satellite images from 2006–2009 (sampling episode 2), and satellite images from 2018–2019 (sampling episode 3). In all four study areas the count of ALD and RTS, and the area of bare soil they exposed, was greater during the first or second sampling episode than the third sampling episode, in spite of record high mean annual temperatures in 2014–2019. One study area had frozen debris lobes (FDL) in addition to ALD and RTS. In that study area the bare ground exposed by destabilization and rapid movement of FDL was greatest in the third sampling episode, probably as a result of deep thaw and talik formation. The destabilization of FDL in episode 3 was probably a long‐term consequence of warming and permafrost loss, while the observed pulses of ALD and RTS in episodes 1 and 2 were closely tied to short‐term deep thaw events in areas where the underlying permafrost remained stable.

Developing and Testing a Deep Learning Approach for Mapping Retrogressive Thaw Slumps

“…The ArcticNet database [84] is the first remote sensing image database with a spatial focus on the Arctic, but this is limited to wetlands. For RTS, most openly accessible high-resolution polygon datasets are available for NW Canada [17,57], Alaska [25] and China [51,85]. For other studies, only RTS centroid coordinates are often made available in public archives [16], or detailed data are not accessible.…”

“…Fairly well-studied regions for the occurrence of thaw slumps are typically clustered and located in former ice-marginal regions of the Laurentide Ice Sheet in NW Canada, most notably the Peel Plateau [17,21] and Banks Island [16], or moraines of formerly glaciated mountain ranges, e.g., the Brooks Range in northern Alaska [20,25]. Intensively studied regions in Siberia include the Yamal Peninsula [13,26], Kolguev Island [27], Bolshoy Lyakhovsky Island [22] and the Yana Basin with its famous Batagaika mega slump [14,28].…”

Glacial Lake Area Change and Potential Outburst Flood Hazard Assessment in the Bhutan Himalaya

“…While adding hazard factors does not necessarily improve the efficiency of the GLOF evaluation methods, we acknowledge that in future studies, integrating ground temperature and permafrost modelling, may provide even more robust results (Allen et al, 2019). Alpine regions elsewhere have exhibited increasing ground temperature and thawing of permafrost leading to slope failure (Haberkorn et al, 2021;Swanson, 2021), which is the key cause of dam overtopping of glacial lakes. However, our recommendations are made within the scope of freely available remote sensing imagery, although we acknowledge that novel field-based data can provide more appropriate information.…”

Ongoing Landslide Deformation in Thawing Permafrost

“…Maximum and mean temperatures during summer months are similar throughout the record. Minimum and mean temperatures during the coldest winter months (January–March) were relatively high in both 2018 and 2019 (Figure 3b, Swanson, 2021).…”

“…Under these conditions, discontinuous permafrost is expected to degrade rapidly (Panda et al., 2014; Pastick et al., 2015), resulting in drastic changes to groundwater hydrology (Walvoord & Kurylyk, 2016) and facilitating the initiation of shallow‐angle landslides (Patton et al., 2019; Swanson, 2021). Shallow‐angle permafrost landslides have been documented elsewhere in the Denali Park Road corridor (Patton et al., 2020), Canada (e.g., Blais‐Stevens et al., 2015; Lewkowicz, 2007; Zwieback et al., 2019), Russia (Khak & Kozyreva, 2012; Zwieback et al., 2018), and other parts of Alaska (Bowden et al., 2008; Daanen et al., 2012; Gooseff et al., 2009; Swanson, 2021). Although increased evapotranspiration rates may result in lower soil moisture over the course of the year (Rupp & Loya, 2008), changes to storm intensity will continue to promote rain‐induced and thaw‐induced landslides.…”