Abstract. Juvfonne is a small ice patch (~0.1 km2) in Jotunheimen, southern Norway, and contains the oldest ice dated in Norway so far. More than 600 artefacts have been detected along the margin. Since 2010 annual investigations of mass balance with point measurements of snow accumulation and ablation have been carried out together with surface elevation and ice patch extent measurements. The outline mapping conducted between 2010 and 2025 demonstrates that the extent of Juvfonne undergoes continuous changes along the entire margin, varying from year to year. The decrease in area from 2010 to 2024 is 46 % from 0.149 km2 to 0.081 km2. Ice thickness measurements conducted in September 2025 reveal a current maximum thickness of less than 9 meters and an interpolated mean thickness of < 3 meters. Repeat surface elevation surveys from lidar and UAV surveys reveal that Juvfonne has lost 73 % of its volume between 2011 and 2025 and thinned on average 4 m (0.30 m a-1), the value is sensitive to the outlines used. We compare the mass changes of Juvfonne with neighbouring glaciers in the Galdhøpiggen massif for the period 2011–2020 using repeated lidar surveys revealing that Juvfonne has had a smaller surface thinning than neighbouring glaciers over this period. Interpretation of data from two nearby automatic weather stations show that deposition of windblown snow on Juvfonne causes more snow accumulation than in the surroundings. The snow accumulation is dependent on wind direction and speed. Major snowfall events are associated with storms or synoptic cold fronts with westerly winds and short-term storm events can contribute greatly to the total accumulation. Ablation is related to cumulative positive degree days, but also to winter balance. Results from a Summer Melt Potential Index for the period 2010–2025 reveal a significant intensification of compounding melt events driven by the synergy of temperature, wind, and atmospheric moisture. Juvfonne prevails due to drifting snow and is controlled by topography and can fill up after years with surface lowering. However, the reduction in area and volume over the period 2010–2025 reveals that Juvfonne is vulnerable to the current warming and its current ice may completely vanish with a few warm summers.

Landslides in glacial and periglacial environments are increasingly affected by climate change, with sudden failures reported in high mountain regions and the Arctic. The complex mechanisms behind these events are often poorly understood due to a lack of dense in situ data. We investigate two slow-moving landslides in Arctic Norway (70° N), the Jettan and Gámanjunni landslides, located approximately 10 km apart: Jettan, a complex slide in micaschist and calcite marble situated below the permafrost boundary, and Gámanjunni, a rotational slide in micaschist situated above the permafrost boundary. Using over a decade of multi-physics observations, including geodetic, borehole, seismic, and hydrological data, we examine surface and subsurface deformation. Both landslides display similar seasonal surface velocity patterns, with peaks in spring and autumn, likely influenced by pore-water infiltration. At Jettan, twelve years of inclinometer data in boreholes reveal a transition from steady state to seasonal deformation in two shear zones. Since 2020, spring accelerations have intensified in years coinciding with deeper snowpacks and associated melt. These observations, together with statistical modeling, suggest that the shear-zones are becoming increasingly localized and sensitive to pore-water pressure. Conversely, autumn acceleration is not seen in localized shear zones but manifests as distributed volumetric deformation. Seismic velocity variations within the landslide body also exhibit seasonal patterns that correspond with geodetic velocity, interpreted as changes in landslide rigidity due to water infiltration. This integrated analysis of surface and subsurface data offers new insights into the evolving deformation of Arctic landslides, emphasizing the influence of hydrological forcings on both seasonal and long-term deformation processes.

Blockfields cover mountain plateaus and low angle slopes in present and former periglacial environments, and their formation, evolution and implications for past glaciations are widely debated. To establish constraints on the life span of blockfields under subaerial conditions (when not covered by a glacier/ice sheet), we analyze frost cracking as the main weathering agent by numerical modeling of the frost cracking intensity (FCI). We focus on the entire block-covered area of Tron Mountain, southern Norway, which stretches from 1650 to 1100 m a.s.l., with simulations extending over an 80-year period (1941 – 2020). The CryoGrid community model is used to calculate the subsurface thermal regime and FCI at 30m resolution, based on downscaled climate reanalysis data. We investigate two typical blockfield stratigraphies: 1) a deep, upper layer of coarse blocks with significant air-filled pores overlying jointed and weathered bedrock, and 2) coarse blocks with fine-grained sediment filling the voids between the blocks. FCI values over the entire Tron Mountain show a strong dependence on stratigraphy, with values being generally five times lower for the air-filled than for the sediment-filled stratigraphy. Furthermore, in the climate setting at Tron Mountain, FCI decreases with elevation for the air-filled stratigraphy, while increasing with elevation for the sediment-filled stratigraphy. Throughout the 80-year period, interannual FCI variability was very high, with standard deviations of up to 60 and 100% from the average. We finally simulate FCI for an elevation-dependent stratigraphic scenario that mimics the observed transition from the air-filled stratigraphy in the summit area to the sediment-filled stratigraphy at lower elevations below around 1350 m a.s.l. In this case, the highest FCI values occur in a zone between 100 and 300 vertical meters below the summit, with relatively low values for the summit itself and the lower slopes. This pattern was observed consistently for all of the analyzed decades and may have important implications for weathering processes, as well as downslope mass movement on the scale of the mountain massif. Enhanced frost weathering occurs in areas with fine-grained sediment at the surface, while blocky, air-filled surface layers are more protected from frost weathering and thus erosion. As frost cracking leads to the production of fine-grained weathering products, the air-filled block layers gradually fill up with fine sediments, which again enhances frost cracking. Such a positive feedback may constitute a differential erosion mechanism for frost-related weathering and erosion in cold regions.

Rock glaciers, composed of debris and ice, are widely distributed across cold mountain regions worldwide. Although research on rock glaciers is gaining momentum, the distinct behaviour of rock glaciers in the marginal periglacial environments remains poorly understood. This study combines remote sensing and in situ methods to characterize transitional rock glaciers in the Carpathian Mountains. We used Persistent Scatterer Interferometry (PSInSAR) on Sentinel-1 images (2015-2020) to detect slope movements associated with rock glaciers and differential GNSS measurements (2019-2021) to track horizontal movement of 25 survey markers. Continuous ground temperature and winter snow cover bottom temperature (BTS) measurements examined energy exchange fluxes affecting these rock glaciers. Geophysical surveys (electrical resistivity tomography and refraction seismic tomography), and petrophysical joint inversion (PJI) quantified ice content in one rock glacier. PSInSAR identified 92 moving areas (MAs) with slow displacement (<5 cm yr(-1)) mostly between 2000 and 2300 m, where solar radiation was minimal. Near-surface thermal data from four rock glaciers suggest favourable conditions for permafrost persistence, largely driven by internal ventilation processes (e.g., advection heat fluxes) throughout the winter. BTS confirmed very low ground surface temperatures over much of the investigated rock glaciers, particularly in their upper parts and within the MAs. Geophysical investigations reveal ice-poor permafrost remnants in the Galesu rock glacier, while PJI modelling estimated a low ground ice content (similar to 18 %) in its upper sector. At this site, surface displacements stem from active layer deformation, not permafrost creep. At two other sites, dGNSS markers moved consistently toward rock glacier fronts, indicating permafrost creep. Regarding activity status, the majority of rock glaciers in the Retezat Mountains were categorized as relict, with only 21 % classified as transitional. Transitional rock glaciers occur 150 m higher and are slightly smaller than relict ones.

Geophysical monitoring becomes more and more popular in permafrost environments due to its remarkable success to detect permafrost thawing and spatio-temporal changes in the ground ice content. Mostly geoelectric methods such as Electrical Resistivity Tomography (ERT) are applied due to the strong differences in the electrical properties between frozen and unfrozen state. However, seismic properties also change markedly upon freezing/thawing and time-lapse refraction seismic tomography (RST) has been shown to be applicable to permafrost over smaller time scales (e.g., Hilbich 2010). The reason why only few studies employ long-term seismic monitoring in permafrost is probably due to the higher logistical effort required.At two Swiss permafrost monitoring sites (Schilthorn and Stockhorn) yearly RST surveys are conducted using the same setup for more than 15 years, in addition to standard borehole temperature, climatic and ERT measurements (www.permos.ch). The monitoring aim is to image the interannual changes of the thickness of the active layer as well as differences in ice content within the permafrost layer below.Additional long-term observations are available from RST (and contemporary ERT) surveys from several mountain permafrost sites in Norway that were initially conducted to characterise permafrost conditions around boreholes drilled in 1999/2008 (Juvvasshoe/Jotunheimen), and 2007/2008 (Iskoras/Finnmark, Guolasjavri/Troms, and Tronfjell, cf. Isaksen et al. 2011, Farbrot et al. 2013). These surveys were repeated with the same geometry in 2019 after 11 years in northern Norway, and after 8 and 20 years in southern Norway. As for the Swiss sites, temperatures from all these boreholes show a clear warming trend over the last 1-2 decades (Etzelmüller et al, 2020, 2023).We here present the observed long-term changes in electrical resistivity and seismic P-wave velocity based on a) annually repeated measurements in the Swiss Alps, and b) on long-term repetition in northern and southern Norway. The geophysical changes are related to the observed borehole temperature increase during the same period (Etzelmüller et al. 2023) and analysed with respect to climate-induced thawing. We evaluate the advantages and disadvantages of seismic monitoring compared to the more standard ERT monitoring. Finally, the results are also analysed with respect to their suitability for future ERT-seismic joint inversion approaches in a monitoring context. ReferencesEtzelmüller B, Guglielmin M, Hauck C, Hilbich C, Hoelzle M, Isaksen K, Noetzli J, Oliva M and Ramos M 2020. Twenty years of European mountain permafrost dynamics—the PACE legacy. Environ. Res. Lett. 15 104070 DOI 10.1088/1748-9326/abae9dEtzelmüller B, Isaksen K, Czekirda J, Westermann S, Hilbich C, Hauck C 2023. Rapid warming and degradation of mountain permafrost in Norway and Iceland. The Cryosphere. 17.5477-5497.10.5194/tc-17-5477-2023.Farbrot H, Isaksen K, Etzelmüller B, Gisnås K 2013. Ground Thermal Regime and Permafrost Distribution under a Changing Climate in Northern Norway. Permafrost Periglac.,24(1):20-38. https://doi.org/10.1002/ppp.1763Isaksen K, Ødegård RS, Etzelmüller B, Hilbich C, Hauck C, Farbrot H, Eiken T, Hygen HO, Hipp T 2011. Degrading mountain permafrost in southern Norway - spatial and temporal variability of mean ground temperatures 1999-2009. Permafrost Periglac.,22(4):361-377, https://doi 10.1002/ppp.728.Hilbich C 2010. Time-lapse refraction seismic tomography for the detection of ground ice degradation, The Cryosphere, 4, 243–259, https://doi.org/10.5194/tc-4-243-2010, 2010.

In Central Asia, the ground thermal regime is strongly affected by the interplay between topographic factors and ecosystem properties. In this study, we investigate the governing factors of the ground thermal regime in an area in Central Mongolia, which features discontinuous permafrost and is characterized by grassland and forest ecosystems. Miniature temperature dataloggers were used to measure near-surface temperatures at c. 100 locations throughout the 6 km2 large study area, with the goal to obtain a sample of sites that can represent the variability of different topographic and ecosystem properties. Mean annual near-surface ground temperatures showed a strong variability, with differences of up to 8 K. The coldest sites were all located in forests on north-facing slopes, while the warmest sites are located on steep south-facing slopes with sparse steppe vegetation. Sites in forests show generally colder near-surface temperatures in spring, summer and fall compared to grassland sites, but they are warmer during the winter season. The altitude of the measurement sites did not play a significant role in determining the near-surface temperatures, while especially solar radiation was highly correlated. In addition, we investigated the suitability of different hyperspectral indices calculated from Sentinel-2 as predictors for annual average near-surface ground temperatures. We found that especially indices sensitive to vegetation properties, such as the Normalized Difference Vegetation Index (NDVI), show a strong correlation. The presented observations provide baseline data on the spatiotemporal patterns of the ground thermal regime which can be used to train or validate modelling and remote sensing approaches targeting the impacts of climate change.

Permafrost landscapes are becoming increasingly susceptible to widespread thaw due to climate change. Collating historical and ongoing data are critical for assessing permafrost conditions and spatiotemporal changes. Electrical resistivity tomography (ERT) is a geophysical technique that has become standard practice for characterizing permafrost. However, resistivity data—particularly raw measurements—often go unpublished and unshared, resulting in missed opportunities for knowledge exchange and collaboration. To fill this gap, we created the Canadian Permafrost Electrical Resistivity Survey database and established clear guidelines for data archival and reuse. Here, we present the first release of the database, which currently houses 280 ERT datasets, including standardized metadata, collected between 2008 and 2022 in British Columbia, Labrador, Northwest Territories, Québec, Yukon, and Alaska. These data present unique opportunities to better understand spatial and temporal variability of permafrost conditions across North America.

We perform a first permafrost higher education curriculum survey in Norden. Permafrost is part of the education within both bio- and geosciences and engineering, and the variation in educational activities reflect this. Five permafrost-specific geoscience and engineering permafrost courses exist, whereas there are 23 bachelor and 25 master courses with a permafrost content ranging from 1% to 50 %. The is large potential and clear needs for closer permafrost teaching collaboration. This could focus on permafrost course development, teaching methods, sharing practical experiences including fieldwork and further developing the educational offer. Such collaboration could establish: 1) An online, joint Nordic specific course on permafrost, sharing the special permafrost competences existing across the universities using digital teaching tools, 2) Nordic collaboration on developing joint, both general but also specific, PhD courses on permafrost, 3) Lifelong education in permafrost, and 4) Internships a part of active permafrost education to better meet the future employers and society’s needs. The Nordic region might also gain largely from establishing an overview-providing interdisciplinary joint Nordic course aiming to characterize the region and its diversity broadly including both natural and social sciences, and naturally covering different topics including permafrost and seasonally frozen ground. The mapping done for this paper will function as a first overall roadmap catalogue providing an overview of all offered courses on permafrost. The overall outcome of our survey shows large potential for increased and deeper inter-university collaboration for further developing joint permafrost higher education both in the form of courses and other educational activities between institutions across Norden, and potentially with ambitions for joint permafrost degrees between several institutions. Based on the presented results and the mapped different future plans for permafrost education across Norden, we discuss the implications of our results, specifically concerning the potential for increased collaboration in Nordic permafrost education. These focus on permafrost course development, teaching methods, sharing practical experiences including fieldwork and further developing the educational offer. In more detail increased collaboration could establish: 1) An online, joint Nordic-specific course on permafrost, sharing the special permafrost competences existing across the universities using digital teaching tools, 2) Nordic collaboration on developing joint PhD courses on permafrost, 3) Lifelong education in permafrost, and 4) Internships as part of active permafrost education to better meet the needs of future employers and society. The Nordic region might also gain largely from establishing an interdisciplinary joint Nordic course, aiming to characterize the region and its diversity broadly and including both natural and social sciences, and naturally covering different topics including permafrost and seasonally frozen ground.

Computer modeling of sporadic and isolated patches of mountain permafrost distribution is difficult to implement without overestimating it. The main challenge is to determine the very areas where the criteria for permafrost maintenance are met. This paper aims to modeling the permafrost distribution in the Southern Carpathians (SC), a typical marginal periglacial mountain range. For this purpose, a collection of 883 bottom temperature of late winter snow cover (BTS) points was used as a proxy for permafrost presence or absence in order to train several machine learning models. The performances of each model were evaluated with AUC with varying between 0.99 for Maxent and 0.74 for K-nearest neighbors and most models (five) exhibiting values between 0.82 and 0.86. Other tests such as confusion matrices, sensitivity analyses, data shuffling, and data size reduction tests indicated that Maxent, AdaBoost, and support vector machine offered the best results while logistic regression, neural network, and gradient boosting exhibited rather poor permafrost distributions. The final ensemble median model indicated a total permafrost area of 19.2 km2 occupying 1%-9% of the alpine area of the studied massifs. NDVI proved crucial for permafrost prediction because it allows delimiting the debris surfaces where permafrost is probable.

The ground thermal regime has a profound impact on geomorphological processes and has been suggested to be particularly important for weathering processes in periglacial environments. Several frost -related damage indices have hitherto been developed to link climate and frost weathering potential in bedrock, although only for individual points or grid cells. Here, we model ground temperature and frost weathering potential in steep rock walls in the Jotunheimen Mountains, southern Norway, along a two-dimensional profile line for the Younger Dryas Stadial-Preboreal transition (c. 11.5 ka), the Holocene Thermal Maximum (c. 7.5 ka), the Little Ice Age (1750), and the 2010s. We use an established heat flow model and frost -cracking index based on the ice segregation theory. A central innovation of our model treatment is the implementation of ensemble simulations using distributions of automatically mapped crack radii in a rock wall, whereas previous frost damage models considered only a single characteristic crack radius. Our results allowed for the identification of sites with enhanced frost weathering. Such sites are typically found between rock walls and retreating glaciers, as well as in areas where snow depth changes abruptly, resulting in large thermal gradients. Hence, frost weathering may be highly active during glacier retreat, enhancing the damage to rock walls during deglaciation by adding to the damage from stress release. The coldest climates of the Younger Dryas Stadial-Preboreal transition and the Little Ice Age were generally most favorable for frost cracking. Such timing compares well with the knowledge about the timing of rockfall accumulations in Norway.

Abstract Mountain permafrost, constituting 30% of the global permafrost area, is sensitive to climate change and strongly impacts mountain ecosystems and communities. This study examines 21st century permafrost warming in European mountains using decadal ground temperature data from sixty-four boreholes in the Alps, Scandinavia, Iceland, Sierra Nevada and Svalbard. During 2013–2022, warming rates at 10 metres depth exceed 1 °C dec−1 in cases, generally surpassing previous estimates because of accelerated warming and the use of a comprehensive data set. Substantial permafrost warming occurred at cold and ice-poor bedrock sites at high elevations and latitudes, at rates comparable to surface air temperature increase. In contrast, latent heat effects in ice-rich ground near 0 °C reduce warming rates and mask important changes of mountain permafrost substrates. The warming patterns observed are consistent across all sites, depths and time periods. For the coming decades, the propagation of permafrost warming to greater depths is largely predetermined already.

near-surface temperature measurements in three blockfields in Norway and Svalbard raw data to the manuscript 'Near-surface temperatures and potential for frost weathering in blockfields in Norway and Svalbard', submitted to Earth Surface Processes and Landforms

With the EU-funded PACE (Permafrost and Climate in Europe) project at the turn of this century, several deep boreholes (100 m+) were drilled in European mountain sites, including in mainland Norway, Svalbard and Sweden. During other projects from 2004 and the International Polar Year (IPY) period in 2006–2007, several additional boreholes were drilled in different sites in both Norway and Iceland, measuring temperatures along both altitudinal and latitudinal gradients. At most sites, multi-temporal geophysical soundings are available using electrical resistivity tomography (ERT). Here, we study the development of permafrost and ground temperatures in mainland Norway and Iceland based on these data sets. We document that permafrost in Norway and Iceland is warming at a high rate, including the development of taliks in both Norway and Iceland in response to global climate change during the last 20 years. At most sites, ground surface temperature (GST) is apparently increasing more strongly than surface air temperature (SAT). Changing snow conditions appear to be the most important factor for the higher GST rates. Modelling exercises also indicate that the talik development can be explained by both higher air temperatures and increasing snow depth.

The CryoGrid community model is a flexible toolbox for simulating the ground thermal regime and the ice-water balance for permafrost and glaciers, extending a well-established suite of permafrost models (CryoGrid 1, 2, and 3). The CryoGrid community model can accommodate a wide variety of application scenarios, which is achieved by fully modular structures through object-oriented programming. Different model components, characterized by their process representations and parameterizations, are realized as classes (i.e., objects) in CryoGrid. Standardized communication protocols between these classes ensure that they can be stacked vertically. For example, the CryoGrid community model features several classes with different complexity for the seasonal snow cover, which can be flexibly combined with a range of classes representing subsurface materials, each with their own set of process representations (e.g., soil with and without water balance, glacier ice). We present the CryoGrid architecture as well as the model physics and defining equations for the different model classes, focusing on one-dimensional model configurations which can also interact with external heat and water reservoirs. We illustrate the wide variety of simulation capabilities for a site on Svalbard, with point-scale permafrost simulations using, e.g., different soil freezing characteristics, drainage regimes, and snow representations, as well as simulations for glacier mass balance and a shallow water body. The CryoGrid community model is not intended as a static model framework but aims to provide developers with a flexible platform for efficient model development. In this study, we document both basic and advanced model functionalities to provide a baseline for the future development of novel cryosphere models.

Determining the link between permafrost and the displacement rates of large unstable rock-slopes (LURSs) is fundamental for understanding future hazard scenarios and establishing appropriate management strategies. From an inventory of >500 LURSs in Norway, we investigate the controls of those with available information on their displacement rates (299 LURSs), presenting the first statistical evidence of permafrost as the main driver of displacement rates of LURSs. The probability for a LURS to displace if permafrost is present now or was during the Little Ice Age (LIA) is around 2.1 times higher than if permafrost was already absent during the LIA. This probability is 1.5 times higher for LURSs with current permafrost than for LURSs with permafrost during the LIA that has since melted. Therefore, our findings enrich the classical conception that warming of permafrost increases displacement rates of LURSs, by showing that the complete thawing of permafrost can result in a decrease in displacement rate or even a complete halt of displacement.

The ground thermal regime and permafrost development have an important influence on geomorphological processes in periglacial regions and ultimately landscape development. About 10 % of unstable rock slopes in Norway are potentially underlain by widespread permafrost. Permafrost thaw and degradation may play a role in slope destabilisation, and more knowledge about rock wall permafrost in Norway is needed to investigate possible links between the ground thermal regime, geomorphological activity and natural hazards. We assess spatio-temporal permafrost variations in selected rock walls in Norway over the last 120 years. Ground temperature is modelled using the two-dimensional ground heat flux model CryoGrid 2D along nine profiles crossing instrumented rock walls in Norway. The simulation results show the distribution of permafrost is sporadic to continuous along the modelled profiles. Results suggest that ground temperature at 20 m depth in steep rock faces increased by 0.2 ∘C per decade on average since the 1980s, and rates of change increase with elevation within a single rock wall section. Heat flow direction is primarily vertical within mountains in Norway. Nevertheless, narrow ridges may still be sensitive to even small differences in ground surface temperature and may have horizontal heat fluxes. This study further demonstrates how rock wall temperature increase rates and rock wall permafrost distribution are influenced by factors such as surface air temperature uncertainties; surface offsets arising from the incoming shortwave solar radiation; snow conditions on, above and below rock walls; and rock wall geometry and size together with adjacent blockfield-covered plateaus or glaciers.

Ground temperatures in coarse, blocky deposits such as mountain blockfields and rock glaciers have long been observed to be lower in comparison with other (sub)surface material. One of the reasons for this negative temperature anomaly is the lower soil moisture content in blocky terrain, which decreases the duration of the zero curtain in autumn. Here we used the CryoGrid community model to simulate the effect of drainage on the ground thermal regime and ground ice in blocky terrain permafrost at two sites in Norway. The model set-up is based on a one-dimensional model domain and features a surface energy balance, heat conduction and advection, as well as a bucket water scheme with adjustable lateral drainage. We used three idealized subsurface stratigraphies, blocks only, blocks with sediment and sediment only, which can be either drained (i.e. with strong lateral subsurface drainage) or undrained (i.e. without drainage), resulting in six scenarios. The main difference between the three stratigraphies is their ability to retain water against drainage: while the blocks only stratigraphy can only hold small amounts of water, much more water is retained within the sediment phase of the two other stratigraphies, which critically modifies the freeze–thaw behaviour. The simulation results show markedly lower ground temperatures in the blocks only, drained scenario compared to other scenarios, with a negative thermal anomaly of up to 2.2 ∘C. For this scenario, the model can in particular simulate the time evolution of ground ice, with build-up during and after snowmelt and spring and gradual lowering of the ice table in the course of the summer season. The thermal anomaly increases with larger amounts of snowfall, showing that well-drained blocky deposits are less sensitive to insulation by snow than other soils. We simulate stable permafrost conditions at the location of a rock glacier in northern Norway with a mean annual ground surface temperature of 2.0–2.5 ∘C in the blocks only, drained simulations. Finally, transient simulations since 1951 at the rock glacier site (starting with permafrost conditions for all stratigraphies) showed a complete loss of perennial ground ice in the upper 5 m of the ground in the blocks with sediment, drained run; a 1.6 m lowering of the ground ice table in the sediment only, drained run; and only 0.1 m lowering in the blocks only, drained run. The interplay between the subsurface water–ice balance and ground freezing/thawing driven by heat conduction can at least partly explain the occurrence of permafrost in coarse blocky terrain below the elevational limit of permafrost in non-blocky sediments. It is thus important to consider the subsurface water–ice balance in blocky terrain in future efforts in permafrost distribution mapping in mountainous areas. Furthermore, an accurate prediction of the evolution of the ground ice table in a future climate can have implications for slope stability, as well as water resources in arid environments.

The importance of frost weathering processes has long been discussed in the context of cold-climate landscape evolution. The 9 % volumetric expansion of in situ water when it freezes to ice was initially held responsible for generating the stresses that create and widen cracks in rocks. This theory has since been challenged by the theory of ice segregation in rocks, in which the growth of ice lenses is supplied by additional water that is drawn to the freezing front. Numerical modelling and laboratory experiments suggest that segregated ice growth can generate enough stress to cause rock damage and is most intense between approximately -8 and -3 ℃ (the precise range depends on rock properties), in the so-called frost cracking window (FCW). The two theories of weathering have different implications for landscape evolution: (1) if in situ volumetric expansion is more important, most frost weathering should occur close to the freezing point, (2) if ice lensing is more important, most frost weathering should occur in the FCW. For the latter theory, several frost weathering indices have been developed based on such factors as the time spent vulnerable to cracking within the FCW, the magnitudes of ground temperature gradients that induce water transport, and other factors that affect water availability. In this study, we model ground temperature using the ground heat flux model CryoGrid 2D (Myhra et al., 2017) and apply the one-dimensional frost weathering index proposed by Rempel et al. (2016), where frost weathering potential is assumed to be correlated with porosity changes that accompany gradients in water flux. Here, we adjust the frost weathering index so that frost weathering potential is modeled in two dimensions. Our results predict spatial and temporal patterns of frost weathering in rock walls that can be tested in the field. References Myhra, K. S., Westermann, S., & Etzelmüller, B. (2017). Modelled distribution and temporal evolution of permafrost in steep rock walls along a latitudinal transect in Norway by CryoGrid 2D. Permafrost and Periglacial Processes, 28(1), 172-182. doi: 10.1002/ppp.1884. Rempel, A. W., Marshall, J. A., & Roering, J. J. (2016). Modeling relative frost weathering rates at geomorphic scales. Earth and Planetary Science Letters, 453, 87-95. doi:10.1016/j.epsl.2016.08.019