Mountain Permafrost Research Articles

A quasi‐continuous long‐term (5 Ma) Mid‐European mountain permafrost record based on fluvial magnetic susceptibility and its contribution to the explanation of Plio–Pleistocene glaciations

The low field magnetic susceptibility (χLF) measured in the 1116‐m‐long Dévaványa core (Pannonian Basin) is a quasi‐continuous record of the Plio–Pleistocene Mid‐European mountain permafrost development. The continuity of fluvial conditions is confirmed by seismic data, and the detrital origin of magnetite is indicated by frequency‐dependent susceptibility measurements, scanning electron microscope, and hysteresis investigations. The χLF record is correlated to the δ18O curve (LR04) supported by palaeomagnetic data. The colour of samples documents precession and obliquity cycles in local facies variations, but the χLF indicates the dominance of 100‐ka eccentricity cycles in the linked mountainous permafrost events. Comparison with orbital solutions revealed that the long‐term development of permafrost occurs as a result of amplitude modulation of the 100‐ka eccentricity cycles. Increases in amplitude of the 100‐ka cycles inhibits permafrost development due to shortened winters. Thus, if extremes are present, the permafrost regions are limited or disappear, but if the 100‐ka eccentricity cycles are attenuated, permanent frost can extend into the temperate zone. This amplitude modulation may also be responsible for the early glaciations during the Pliocene, for the intensification of Northern Hemisphere glaciation, foreshadows cooling in the forthcoming 405‐ka term, and allows the change from 41‐ka cycles to 100‐ka ones in the Mid‐Pleistocene Transition to be explained. The 41‐ka cycles are the result of obliquity‐controlled changes close to the polar cycles, while 100‐ka cycles occur when the amplitude attenuation of the 100‐ka eccentricity cycles enables extended glaciations that suppress the regular 41‐ka cycles. Higher mountains in the catchments enable higher resolution of permafrost records documenting even smaller glaciations. However, the similarities in the overall trends in χLF records of catchment areas with 1500‐m difference in their altitude is a potential counter‐argument when considering the role of tectonic elevations in the expansions of mountainous permafrost.

Review article: Retrogressive thaw slump characteristics and terminology

Abstract. Retrogressive thaw slumps (RTSs) are spectacular landforms that occur due to the thawing of ice-rich permafrost or melting of massive ground ice, often in hillslope terrain. RTSs occur in the Arctic, the subarctic, and high mountain (Qinghai–Tibet Plateau) permafrost regions and are observed to expand in size and number due to climate warming. As the observation of RTSs is receiving more and more attention due to their important role in permafrost thaw; impacts on topography; mobilization of sediment, carbon, nutrients, and contaminants; and their effects on downstream hydrology and water quality, the thematic breadth of studies increases and scientists from different scientific backgrounds and perspectives contribute to new RTS research. At this point, a wide range of terminologies originating from different scientific schools is used, and we identified the need to provide an overview of variable characteristics of RTSs to clarify terminologies and ease the understanding of the literature related to RTS processes, dynamics, and feedbacks. We review the theoretical geomorphological background of RTS formation and landform characteristics to provide an up-to-date understanding of the current views on terminology and underlying processes. The presented overview can be used not only by the international permafrost community but also by scientists working on ecological, hydrological, and biogeochemical consequences of RTS occurrence and by remote-sensing specialists developing automated methods for mapping RTS dynamics. The review will foster a better understanding of the nature and diversity of RTS phenomena and provide a useful base for experts in the field but also ease the introduction to the topic of RTSs for scientists who are new to it.

Modelling the effect of free convection on permafrost melting rates in frozen rock clefts

Abstract. This research develops a conceptual model of a karst system subject to mountain permafrost. The transient thermal response of a frozen rock cleft after the rise in the atmospheric temperature above the melting temperature of water is investigated using numerical simulations. Free convection in liquid water (i.e. buoyancy-driven flow) is considered. The density increase in water from 0 to 4 °C causes warmer meltwater to flow downwards and colder upwards, resulting in significant enhancement of the heat transferred from the ground surface to the melting front. Free convection increases the melting rate by approximately an order of magnitude compared to a model based on thermal conduction in stagnant water. The model outcomes are compared qualitatively with field data from the Monlesi ice cave (Switzerland) and confirm the agreement between real-world observations and the proposed model when free convection is considered.

Dynamics and internal structure of a rock glacier: Inferring relationships from the combined use of differential synthetic aperture radar interferometry, electrical resistivity tomography and ground‐penetrating radar

AbstractRock glaciers are characteristic landforms in alpine environments originating from the movement of permanently frozen ground. Hereby, rock glacier velocity (RGV) is an important parameter for understanding the effects of climate change on mountain permafrost. Although understanding of rock glacier dynamics has increased during the last decades, linking small‐scale surface kinematics to sub‐surface properties and heterogeneities remains a challenge. To address this gap, we conducted geophysical surveys (electrical resistivity tomography [ERT] and ground‐penetrating radar [GPR]) along two profile lines of 450 and 950 m in length on a rock glacier in the Central Swiss Alps. Additionally, RGV was derived from Sentinel‐1 differential synthetic aperture radar interferometry (DInSAR) to quantify annual east–west displacement and elevation change as well as seasonal acceleration during the snow‐free summer months with a ground sampling distance of 5 m. Our results show that movement angle and seasonality are highly associated with different patterns in sub‐surface structure. These different movement patterns are linked to subunits of different morphological origins. Thereby, we can upscale the geophysical results based on the DInSAR surface movement parameters and outline an area within the study site probably affected by ice of glacial origin. Hence, DInSAR movement angle and seasonality can help to bring local sub‐surface information derived from time‐consuming geophysical investigations into the spatial domain. In this way, a better understanding of the current morphodynamics as well as the past and future evolution of the landform can be reached. Applying the approach to other sites with available geophysical investigations could enhance our knowledge about systematic links between surface kinematics and the internal structure of rock glaciers and other ice‐rich glacial and peri‐glacial landforms, as well as their response to a warming climate.

Current understanding, knowledge gaps, and challenges of mountain permafrost research in the Chilean and Argentinean Andes

Mountain permafrost extends over a vast area throughout the Chilean and Argentinean Andes, making it a key component of these mountain ecosystems. To develop an overview of the current state of knowledge on southern Andean permafrost, it is essential to outline appropriate research strategies in a warmer climate context. Based on a comprehensive review of existing literature, this work identifies eight main research themes on mountain permafrost in the Chilean and Argentinean Andes: paleoenvironmental reconstructions, permafrost-derived landforms inventories, permafrost distribution models, internal structure analysis, hydrogeochemistry, permafrost dynamics, geological hazards, and transitional landscape studies. This extensive review work also highlights key debates concerning the potential of permafrost as a water resource and the factors influencing its distribution. Furthermore, we identified several challenges the scientific community must address to gain a deeper understanding of mountain permafrost dynamics. Among these challenges, we suggest tackling the need to broaden spatial focus, along with the use of emerging technologies and methodologies. Additionally, we emphasize the importance of developing interdisciplinary approaches to effectively identify the impacts of climate change on mountain permafrost. Such efforts are essential for adequately preparing scientists, institutional entities, and society to address future scenarios.

Quantifying the influencing factors of the thermal state of permafrost in Northeast China

In Northeast China, permafrost is controlled by a combination of biotic, climatic, physiographic, and anthropogenic factors. Due to the complexity of these governing or influencing factors, it is challenging to exactly describe the features of the Xing’an permafrost in Northeast China. By integrating remote sensing (RS) and geographic information system (GIS) technologies, we have quantified these influencing factors of permafrost changes as an important approach to understanding the nature of latitudinal and mountain permafrost in Northeast China at the mid-latitudes in the Northern Hemisphere. In this study, we combine Geographical Detector (Geodetector) model, trend analysis, and multi-source RS data to quantify the controlling or influencing factors of permafrost thermal state and of permafrost changes, and explain the interactions among permafrost, environment, and climate. The results indicate that, at the regional scale, changes in the thermal state of permafrost are primarily governed or influenced by mean annual land surface temperature (MALST), precipitation, and snow cover duration (SCD). Topographic factors also affect the spatial patterns of permafrost development. Additionally, in the context of climate warming, the insulation effect of snow cover on the permafrost is weakened, or has been weakening. Moreover, the interactive effects among various factors significantly enhance their explanatory power for changes in the thermal state of permafrost. The study emphasizes the complexity of the interactions among permafrost, climate, and the environment, and highlights the significance of understanding these interactions for regional socio-economic development, ecological management, carbon pool stabilization, and research on future climate change in Northeast China.

Comprehensive assessment of rock glaciers in the Himachal Himalayas: Updated inventory and labelling

Rock glaciers are geomorphological features often used as a visible expression of mountain permafrost. These are creeping ice-debris with distinct ridge and furrow structures on the surface with a steep frontal slope. Rock glaciers, being the valuable past permafrost indicators, also have utmost hydrological significance in near future. Therefore, mapping of rock glaciers is an important step in order to understand permafrost regimes better. The Himalayas have large occurrences of these features and this study in Himachal Himalayas complied 789 rock glaciers, covering an area of about 336.2 km2. Different labels based on genesis, location, shape, form, surface relief and activity revealed rock glaciers were mainly derived from talus slopes (239) and exhibited tongue shape (377), primarily found in cirques (531). Most of them were classified as simple units (603) with well-developed surface relief (387), and they were found to be predominantly intact (760). The topographical parameters suggest majority of the rock glaciers are located between 4000 and 4800 m with mean elevation to be 4635 m. These rock glaciers are present at gentle to steep slope gradient (0 to 45°) with curvature ranging between −3.5 and 4.5, and majority showing convex curvature. The slope aspect conducive for formation of rock glaciers in Himachal is northerly (N, NW, NE). Principal geology for these rock glaciers belongs to slate, phyllite, quartzarenite, limestone and meta basics. The climatic parameters and indices also affect the rock glaciers occurrence significantly. The mean land surface temperature (LST) for majority rock glaciers lies between 0 and −15°C. While, the mean NDSI of all the rock glaciers varies from 0.04 to 0.68 and mean NDVI varies from −0.06 to 0.08. Overall, the inventory along with labels is a valuable database for understanding the distribution and characteristics of rock glaciers in the Himachal Himalayas.

Permafrost Distribution in the Southern Carpathians, Romania, Derived From Machine Learning Modeling

ABSTRACTComputer 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.

Mountain permafrost landslides: Experimental study investigating molard formation processes

Landslides triggered by degrading mountain permafrost pose an increasing risk to life and infrastructure in mountain regions due to current climate change trends. Because discontinous mountain permafrost is not directly detectable by remote sensing, permafrost molards offer a way of indirectly detecting its location and state. Permafrost molards are cones of loose debris that are associated with landslide deposits. They originate from ice-cemented blocks of sediment that are transported downslope with the landslide. These ice-cemented blocks are fragmented parts of the permafrost initially located in the landslide source area. Over time, these blocks degrade into conical mounds with diameters typically ranging from decimeters up to 40 m. They indicate the presence of an area of degrading permafrost at the level of the detachment zone. The physical processes that lead to the formation of molards from the ice-cemented blocks have not yet been studied in detail. Therefore, we perform an experimental study to recreate molards in a controlled laboratory environment and investigate the key formation processes. We downscale the molards to an initial cube side length of ~30 cm, and reduced the model's complexity by using two different types of gravel with a defined granulometry and lithology. We quantified the degradation phase by using a novel photogrammetric time-lapse system to detect changes in the digital elevation model between half-hourly time-steps. For the first time, we successfully recreated morphologies resembling molards under controlled laboratory conditions on a decimeter scale. We find the main processes to produce the final molard shape are cascades of grainfall for slightly cohesive sediment, and individual grainfall for non-cohesive sediment. Our experiments reveal three possible cross-section shapes (bell-shaped, triangular, trapezoidal) that correspond to molards that can be found in the field. Along with these field observations, we suggest that it may be possible to identify the cohesion of a molard's sediment based on its morphology. Together with future field data and experiments investigating the granulometry, ice and clay contents of the initial ice-cemented block, we aim to use molards as a record to better understand the landslide dynamics and state of the mountain permafrost.

Exploring the impact of surface lapse rate change scenarios on mountain permafrost distribution in four dissimilar valleys in Yukon, Canada

A scenario-based approach was used to test air and ground response to warming with and without changes to inverted surface lapse rates in four Yukon valleys. Generally, climate warming coupled with weakening of temperature inversions resulted in the greatest increase in air temperature at low elevations. However, ground temperatures at high elevations showed the greatest response to warming and variability between scenarios due to increased connectivity between air and ground. Low elevations showed less of a response to warming and permafrost was largely preserved in these locations. Local models also predicted higher permafrost occurrence compared to a regional permafrost probability model, due to the inclusion of differential surface and thermal offsets. Results show that the spatial warming patterns in these mountains may not follow those predicted in other mountain environments following elevation dependent warming (EDW). As a result, the concept of EDW should be expanded to become more inclusive of a wider range of possible spatial warming distributions. The purpose of this paper is not to provide exact estimations of warming, but rather to provide hypothetical spatial warming patterns, based on logical predictions of changes to temperature inversion strength, which may not directly follow the distribution projected through EDW.

Transient Modeling of Permafrost Distribution From 1986 to 2016 in Mongolia

ABSTRACTThe distribution of permafrost in the southernmost zones is complicated in both time and space. We assessed this complexity by applying transient heat transfer schemes to model permafrost in Mongolia between 1986 and 2016. The modeling took into account the spatial distribution of soil thermal properties and time series of ground temperature profiles observed at 69 borehole sites. Spatial modeling was forced by downscaled ERA5 air temperatures that were further debiased with local meteorological records. The results indicated that permafrost warmed by 0°C to 0.4°C/decade, most significantly in eastern and northern Hangai and at high elevations in the Altai Mountains. The extent of permafrost remained stable, but the active layer was thickened, especially after the late 1990s. Forested wet soils experienced less warming, while temperatures in soils with low organic matter and low moisture content increased by 0.5°C over the modeling period. The lower limits of mountain permafrost were estimated to be between 1320 and 2030 m a.s.l., depending on the latitude. Our permafrost map allows the delineation of a complex distribution of permafrost in Mongolia, which is strongly controlled by the spatially complex topography, landcovers, and soil wetness.

Preconditioning of mountain permafrost towards degradation detected by electrical resistivity

Warming permafrost has been detected worldwide and is projected to continue during the next century by many modelling studies. In mountain regions, this can lead to potentially hazardous impacts on short time-scales by an increased tendency for slope instabilities. However, time scales of permafrost thaw and the role of the ice content are less clear, especially in heterogeneous mountain terrain, where ice content can vary between zero and supersaturated conditions over small distances. Warming of permafrost near the freezing point shows therefore complex inter-annual behaviour due to latent heat effects during thawing and the influence of the snow-cover, which is governed by highly non-linear processes itself. Here, we demonstrate a preconditioning effect within near-surface layers in mountain permafrost that causes non-linear degradation and accelerates thaw. We hypothesise that a summer heat wave, as has occurred in the Central European summers 2003, 2015 and 2022, will enhance permafrost degradation if the active layer and the top of the permafrost layer are already preconditioned, i.e. have reduced latent heat content. This preconditioning can already be effectuated by a singular warm year, leading to exceptionally strong melting of the ground ice. On sloping terrain this ice-loss can be considered as irreversible, as large parts of the melted water will drain during the process, and an equivalent build-up of ice in cold years does not happen on similar time-scales as the melting. We propose a simple geophysical approach based on electrical resistivity tomography surveys that can assess the state of preconditioning in the absence of boreholes. In addition, we will show that resistivity data from a total of 124 permafrost sites in the Andes, Europe, and Antarctic adhere to a distinct power law behaviour between unfrozen and frozen states, which confirms the consistent electrical behaviour of permafrost and active layer materials over a wide range of landforms and material composition.

Discriminating viscous-creep features (rock glaciers) in mountain permafrost from debris-covered glaciers – a commented test at the Gruben and Yerba Loca sites, Swiss Alps and Chilean Andes

Abstract. Viscous-flow features in perennially frozen talus/debris called rock glaciers are being systematically inventoried as part of the global climate-related monitoring of mountain permafrost. In order to avoid duplication and confusion, guidelines were developed by the International Permafrost Association to discriminate between the permafrost-related landform “rock glacier” and the glacier-related landform “debris-covered glacier”. In two regions covered by detailed field measurements, the corresponding data- and physics-based concepts are tested and shown to be adequate. Key physical aspects which cause the striking morphological and dynamic differences between the two phenomena/landforms concern the following: tight mechanical coupling of the surface material to the frozen rock–ice mixture in the case of rock glaciers, contrasting with essential non-coupling of debris to the glaciers they cover; talus-type advancing fronts of rock glaciers exposing fresh debris material from inside the moving frozen bodies, as opposed to massive surface ice exposed by increasingly rare advancing fronts of debris-covered glaciers; and increasing creep rates and continued advance of rock glaciers as convex landforms with structured surfaces versus predominant slowing down and disintegration of debris-covered glaciers as often concave landforms with primarily chaotic surface structure. Where debris-covered surface ice is or has recently been in contact with thermally controlled subsurface ice in permafrost, complex conditions and interactions can develop morphologies beyond simple either–or-type landform classification. In such cases, the remains of buried surface ice mostly tend to be smaller than the lower size limit of “glaciers” as the term is applied in glacier inventories and to be far thinner than the permafrost in which they are embedded.

Topographic Drivers of Permafrost Organic Carbon Accumulation on the Northern Qinghai–Tibet Plateau

ABSTRACTLarge amounts of soil organic carbon (SOC) have accumulated over thousands of years in the northern permafrost regions. However, the SOC accumulation rates and the effects of topography, vegetation, and soil properties on SOC storage remain poorly constrained, leading to large uncertainties in the estimation of SOC storage and its response to warming. Here, we examined SOC stocks, densities, and accumulation rates using field sampling and radiometric dating in areas with different topographic parameters on the northern Qinghai–Tibet Plateau. Results show that SOC density and stock increases with elevation on south‐facing slopes but decreases with elevation on north‐facing slopes. The carbon accumulation rates in the upper 6 m soil are highest (16.32 g C m−2 year−1) in the north‐facing alpine wet meadow and lowest (1.07 g C m−2 year−1) in the south‐facing alpine steppe. Elevation‐, slope‐, and slope aspect‐induced variations in soil properties and vegetation type are the main factors controlling the spatial SOC distribution. These results imply that the topography strongly affects the spatial heterogeneity of SOC in mountainous permafrost regions. Overall, our findings highlight that topographic factors should be further integrated into carbon models of carbon responses to climate change in permafrost‐affected soils.

Geocryological Conditions of Small Mountain Catchment in the Upper Kolyma Highland (Northeastern Asia)

This research presents a comprehensive environmental assessment of a small mountain permafrost catchment of the Anmangynda River in the Upper Kolyma Highland (Northeastern Asia) over the period of 2021–2023. The study reveals significant diversity in climatic, geocryological, and hydrogeological conditions within this confined area, emphasizing the need for extensive field data collection and monitoring in vast permafrost regions with limited data availability. Key findings include variations in ground temperature, maximum seasonal thaw depth, and depths of zero annual amplitudes of ground temperature at different elevations and landscape types. Groundwater and surface flow dynamics within spring aufeis basins exhibit complex geocryological regimes influenced by icing processes. The presence of aufeis and its impact on local hydrology highlight the ecological significance of this phenomenon. Future research should focus on long-term trends in permafrost dynamics and their relationship with climate change, as well as the ecological effects of aufeis formation on local ecosystems. The study underscores the importance of a multi-faceted approach to environmental assessment, incorporating various environmental parameters and processes, to gain a comprehensive understanding of the intricate interactions within the cryosphere and their responses to changing climate conditions. Such knowledge is essential for addressing broader questions related to climate change, ecosystem resilience, and sustainable resource management in Northeastern Siberia.

Review and discussion of modern concepts and its relation to the research in Poland

This paper describes the foundations of the periglacial concept beginning from the introduction of this term by Łoziński in 1909 and 1912. Its etymology along with the meaning and definitions that change over time are analysed in the present paper. Originally derived from geology, periglacial now functions as a geomorphological term. It has been compared with other terms used in the characterisation of cold geographical environments; the role of freezing and ice has been especially emphasised for periglaciology, and the most important types of ice have been highlighted. The present paper aims to show that with the increasing specialisation of research and the evolution of the meaning of the term periglacial, it is still seen as playing an important integrating role. The relation of the periglacial environment and ice to the glacial environment is also presented, showing the places of mutual overlapping of both environments. Old and newly introduced terms related to this concept such as periglacial facies, periglacial landscape, paraglacial, and cryo-conditioning are critically assessed. Finally, a short description of the permafrost in Poland, occurring in two remote and specific places, is presented: the active mountain permafrost covering the alpine belt of the Tatra Mountains about 1900 m a.s.l. and the relict permafrost in the Suwałki area, located in the northern lowland of Poland at a depth of 357 m and below.

Acceleration and interannual variability of creep rates in mountain permafrost landforms (rock glacier velocities) in the European Alps in 1995–2022

Cryospheric long-term timeseries get increasingly important. To document climate-related effects on long-term viscous creep of ice-rich mountain permafrost, we investigated timeseries (1995–2022) of geodetically-derived Rock Glacier Velocity (RGV), i.e. spatially averaged interannual velocity timeseries related to a rock glacier (RG) unit or part of it. We considered 50 RGV from 43 RGs spatially covering the entire European Alps. Eight of these RGs are destabilized. Results show that RGV are distinctly variable ranging from 0.04 to 6.23 m a−1. Acceleration and deceleration at many RGs are highly correlated with similar behaviour over 2.5 decades for 15 timeseries. In addition to a general long-term, warming-induced trend of increasing velocities, three main phases of distinct acceleration (2000–2004, 2008–2015, 2018–2020), interrupted by deceleration or steady state conditions, were identified. The evolution is attributed to climate forcing and underlines the significance of RGV as a product of the Essential Climate Variable (ECV) permafrost. We show that RGV data are valuable as climate indicators, but such data should always be assessed critically considering changing local factors (geomorphic, thermal, hydrologic) and monitoring approaches. To extract a climate signal, larger RGV ensembles should be analysed. Criteria for selecting new RGV-sites are proposed.

Enhancing mountainous permafrost mapping by leveraging a rock glacier inventory in northeastern Tibetan Plateau

ABSTRACT Our understanding of permafrost distribution is still limited, particularly in mountainous areas where highly heterogeneous environments and a lack of reliable field data tend to prevail. The extensive distribution of rock glaciers in the Qilian Mountains, located in the northeastern Tibetan Plateau, offers the opportunity to develop a novel approach for permafrost mapping in mountainous regions. In this study, a total of 1,530 rock glacier records were combined with in situ data to drive machine learning models for estimating permafrost presence. Three machine learning algorithms were adopted, and their accuracies were assessed in both mountains and plains by comparing the mapped permafrost to reserved field data as well as other published permafrost datasets. Among the algorithms tested, the CatBoost model presented the highest accuracy, with an overall accuracy of 83.3%. The model was thus chosen to produce a 250-m resolution permafrost zonation index (PZI) map, which identified a total area of 73.1 × 103 km2 permafrost in the Qilian Mountains, accounting for 39.1% of the area. The map also presented higher accuracy than other published permafrost maps. This study demonstrated that rock glacier records coupled with gradient-boosting machine-learning algorithms can help improve permafrost mapping, especially in the most challenging mountainous permafrost areas.

Roles and activities of local stakeholders facing Alpine permafrost warming: A comparative exploratory analysis of three contexts and networks of actors

Mountain permafrost warming resulting from climate change increases gravitational hazards. This interdisciplinary study compares the networks of actors involved in managing such hazards in three regions of the European Alps. Interviews were conducted with 40 people (members of local authorities, mountain professionals, and private citizens) at the foot of Mont Blanc (Chamonix, France), in the Vanoise massif (France), and in the canton of Valais (Switzerland). Data were analysed qualitatively and quantitatively using interaction matrices and network diagrams. Communal authorities played a central role but partnered with many other public and private actors. In Valais, collaboration to protect infrastructure and inhabited areas was centred around communal and cantonal authorities. In Chamonix, the network of actors gave a significant role to mountain professionals. In Vanoise, the network was less dense and less well-defined, although actors had high expectations regarding awareness-raising and prevention. Sources of tension existed in all three networks, particularly between authorities and mountain professionals. To strengthen community resilience, authorities should develop more mechanisms for citizen participation in risk management.

Multiple Close-Range Geomatic Techniques for the Kinematic Study of the La Paúl Rock Glacier, Southern Pyrenees

Rock glaciers are one of the most representative elements of mountain permafrost. Their study can contribute to modelling climate change and its effect on natural and anthropogenic environments. Therefore, it is crucial to understand the evolution and quantify the changes in these periglacial landforms at a global level. This study aims to present the monitoring work carried out on the Pyrenean rock glacier of La Paúl (42°39′40″N, 0°26′34″E) from 2013 to 2020, employing in situ geomatics techniques to determine the landform surface kinematics accurately. For this purpose, global navigation satellite systems (GNSS), terrestrial laser scanners (TLS), and unmanned aerial vehicles (UAV) photogrammetry techniques were used simultaneously to evaluate their compatibility in quantifying displacements. Based on 2D and 3D analyses, the results demonstrate the high surface activity of the rock glacier, with mean variations reaching 36 cm/year (GNSS) and a distribution of deformations that, although intensified on its western side, are present on the entire surface of La Paúl. This study uses state-of-the-art geomatics techniques to present dependable and updated quantitative data on a periglacial landform’s recent development in under-researched areas, such as the Pyrenean temperate high mountain.