Active layer probing in northern Sweden, northeast Greenland, and central Svalbard indicates active layer thickening has occurred at Circumpolar Active Layer Monitoring (CALM) sites with long‐term, continuous observations, since the sites were established at these locations in 1978, 1996, and 2000, respectively. The study areas exhibit a reverse latitudinal gradient in average active layer thickness

Ground surface and permafrost temperatures in the High Arctic are often considered homogeneous especially when viewed at the scale of climate and environmental models. However, this is generally incorrect due to highly variable, topographically redistributed snow cover, which generates a substantial degree of ground thermal heterogeneity. The objective of this study is to describe and spatially model

The acceleration of permafrost thaw due to warming, wetting, and disturbance is altering circumpolar landscapes. The effect of thaw is largely determined by ground ice content in near‐surface permafrost, making the characterization and prediction of ground ice content critical. Here we evaluate the spatial and stratigraphic variation of near‐surface ground ice characteristics in the dominant forest

During the last 50 ka, cryogenic wedges on the Ordos Plateau formed during three major periods: (i) early local Last Glaciation, ca. 50 ka BP; (iii) local Last Permafrost Maximum(local LPM), 25–19 ka BP; and (v) post‐local LPM, 16–9 ka BP. Cryoturbations mainly formed in the following periods: (ii) pre‐local LPM, 45–30 ka BP and (iv) ~ 20 ka BP. The coldest periods with well‐developed permafrost (i

This paper presents a computational model of the freezing point of soil and the nucleation rate of ice based on the soil volume for saline soils. Physicochemical methods and crystallization theory are used to explore the macroscopic mechanism of water freezing induced by ice crystallization, and the influence of water undercooling is discussed with regard to different soil volumes and salt contents

Automated recognition and delineation of specific landforms and their constituent elements ranks among the most active areas of contemporary geomorphological research. This study contributes to that literature by applying semi‐ and fully automated recognition procedures to upland periglacial geomorphic landscapes. The Cryoplanation Terrace semi‐Automated Recognition (CTAR) algorithm utilizes basic

Whether Arctic and alpine ecosystems will act as a future net sink or source of carbon remains uncertain. The present study investigates ways in which ecosystem (soil and vegetation) and geomorphological (cryogenic disturbance) factors may control or affect the future release of carbon in an alpine permafrost landscape. Rates of ecosystem respiration (Re) were examined using a portable gas analyzer

No abstract is available for this article.

Thermokarst lakes form following the thaw of ice‐rich permafrost and drain after a few decades to millennia. Drained thermokarst lake basins (DTLBs) become epicenters for peat accumulation and re‐aggradation of ice‐rich permafrost. This re‐aggradation of permafrost may be interrupted by subsequent thermokarst lake formation with sufficient disturbance. Thermokarst lakes and DTLBs are abundant near

We present the basic theory of stable isotopes (δ(18O) and δ(D)) of freezing water solutions in the environment set within a water isotope‐augmented version of FREZCHEM(V15). We validate this model with a couple of examples. The isotope‐capable FREZCHEM is simplified to run much faster using set‐piece initial chemistries to calculate the freezing temperature of the remaining water. The fast version

The freezing of sulfate saline soil involves the coupling effect of heat and mass transfer and crystallization deformation. The influence of salt content and temperature on the crystallization of ice and salt was analyzed by using a one‐side freezing experiment. Based on the effect of solute and temperature on water activity, a crystallization kinetics model of ice–water phase change in saline soil

Determining the freezing state and frozen section thickness is fundamental to assessing the development of artificial frozen walls but is commonly difficult or inaccurate because of a limited number and fixed position of thermometer holes under complex field conditions. We report a novel experimental design that measures soil temperature, water content, and ultrasonic properties to monitor movement

The liquid water fraction is one of the most important parameters in the study of saline soils of cold regions, and has great influence on water migration. The freezing temperature and saturated concentration of pore solutions have been investigated according to thermodynamic theory, indicating that pore radius, temperature, and salt concentration are the three main influencing factors. Here, a method

Submarine permafrost is perennially cryotic earth material that lies offshore. Most submarine permafrost is relict terrestrial permafrost beneath the Arctic shelf seas, was inundated after the last glaciation, and has been warming and thawing ever since. As a reservoir and confining layer for gas hydrates, it has the potential to release greenhouse gasses and impact coastal infrastructure, but its

In recent years, new geophysical phenomena have been observed in the high‐latitude regions of continental permafrost. Since 2014 new craters 10–20 m in diameter have been found within the Yamal Peninsula and neighboring regions. They are associated with the emissions of gases, which could have been formed during dissociation of relict gas hydrate deposits due to increases in soil temperature. This

Despite their relevance in alpine environments, rock glaciers remain uncharted in several regions of the globe due to the considerable efforts required in the mapping process. To develop a support tool for rock glacier mapping, this study investigates the feasibility using artificial intelligence to recognize these landforms on satellite optical imagery. The results of this exploratory analysis indicate

Warming conditions across Canada's subarctic and arctic regions are causing permafrost landforms to thaw, resulting in rapid land cover change, including conversion of peat plateaus to wetland and thermokarst. These changes have important implications for northern ecosystems, including shifting controls on carbon uptake and release functions, as well as altering evapotranspiration (ET) rates, which

Permafrost thaw has been widely observed to alter the biogeochemistry of recipient aquatic ecosystems. However, research from various regions has shown considerable variation in effect. In this paper, we propose a state factor approach to predict the release and transport of materials from permafrost through aquatic networks. Inspired by Hans Jenny's seminal description of soil‐forming factors, and

The paper focuses on analysis of macro‐ and micromorphological characteristics of relict slope deposits in Serra da Estrela (Portugal) to understand the significance of different slope processes and paleoenvironmental settings. Micromorphology is a useful sedimentology technique allowing significant advances compared to macroscopic techniques. Results show that different processes are involved in the

Aufeis, also known as an icing or naled, is an accumulation of ice that forms primarily during winter when water is expelled onto frozen ground or ice surfaces and freezes in layers. Process‐oriented aufeis research initially expanded in the 20th century, but recent interest in changing hydrological conditions in permafrost regions has rejuvenated this field. Despite its societal relevance, the controls

Permafrost distribution maps are of importance for environmental assessment, climate system modeling, and practical engineering applications. The scarcity of forcing data and parameters often limits the uses of permafrost models over large areas. However, detailed data are often available in a few subregions through field investigations. In this study, we propose a novel approach for mapping permafrost

Tropical high‐mountain permafrost has a unique thermal regime due to its exposure to strong solar radiation and to rough surface snow morphology, which reduce ground heat transfer from the surface. Latent heat transfer and higher albedo that occur during the snow‐covered season contribute to positive feedback that supports the presence of permafrost. This preliminary study reports on the thermal state

Permafrost on the Qinghai–Tibet Plateau (QTP) has undergone degradation as a result of recent climate change. This may alter the thermo‐hydrological processes and unlock soil organic carbon, and thereby affect local hydrological, ecological, and climatic systems. The relationships between permafrost and climate change have received extensive attention, and in this paper we review climate change for

Permafrost is sensitive to both climate warming and engineering disturbance on the Qinghai–Tibet Plateau (QTP). These factors degrade the stability of infrastructure built on permafrost and reduce its service life. To counter these effects, cooling of the subgrade to lower permafrost temperature forms part of the engineering design on the QTP. Proactive cooling of the subgrade has been used in construction

Evaluating the degradation of permafrost is a major challenge in understanding global warming and its impact on the cryosphere. The Global Cryosphere Watch is promoting actions towards data quality and traceability, to achieve comparability of observations from different permafrost stations. In response to this, a transportable system for on‐site calibrations of permafrost temperature sensors was studied

Arctic slope hydrology studies suggest that water follows preferential subsurface flow paths known as water tracks. While subsurface flow is usually expected to transport only dissolved solids, periglacial studies have indicated some evidence of lessivage associated with flow through sorted patterned ground. We investigated the transport of dissolved and suspended sediments in water tracks on a polar

Taliks are bodies or layers of unfrozen ground in permafrost areas. Recent research on taliks has been driven largely by the potential for release of greenhouse gases as taliks expand, and engineering challenges associated with thawing permafrost. Observations of talik configuration and development have been assisted by advances in geophysical techniques that complement mechanical and thermal measurements

This paper presents the results of mapping inherited cold‐climate landforms and deposits at the Muchów Hills site in the Sudetes, Central Europe (51°N). Bedrock supporting the upper slopes is basalt, with well‐developed columnar jointing, and local relief is of the order of 100 m, whereas the middle and lower slopes are underlain by glacigenic deposits. Characteristic cold‐climate landforms include

No abstract is available for this article.

An increased interest in Arctic environments, mainly due to climate change, has changed the conditions for permafrost research in recent years. This change has been accompanied by a global increase in scientific publications, as well as a trend towards open access publications. We have analyzed abstracts, titles and keywords for publications on permafrost from 1998 to 2017 to identify developments

Late Pleistocene and Holocene ground ice are common throughout the Arctic. Some forms of relict ground ice preserve local meteoric water, and their stable oxygen‐ and hydrogen‐isotope ratios can be used to reconstruct past air temperatures. In this paper, we review the formation and sampling of two forms of relict ground ice—wedge ice and pore ice—and recent (2010–2019) advances in paleoclimatological

Adequate characterization of soil organic carbon (SOC) fractions is essential to elucidate carbon dynamics in permafrost‐affected ecosystems. SOC and its fractions were investigated across alpine ecosystems, including alpine swamp meadows (ASM), alpine meadows (AM) and alpine steppes (AS), in permafrost regions on the Qinghai–Tibet Plateau (QTP), southwest China. The density separation method was used

Express highways are roads of high speed, large capacity, and transportation flexibility. The network of express highways in China has been developed over the last 30 years to accommodate the needs of a growing population and to facilitate economic development. Part of the network is in permafrost regions, where the construction and maintenance of these roads present significant engineering challenges

Climate warming can cause intense changes in regional soil freeze/thaw dynamics and thus exerts strong effects on hydrological processes. Because permafrost conditions vary widely across the Tibetan Plateau (TP), a better understanding the potential influences of permafrost types is helpful to project future hydrological changes. Using multilayer soil temperatures from 45 meteorological stations, this

In the region of the Stepanek rock glacier (69°19′/69°26′W, 32°55′/32°59′S), in the Province of Mendoza, Argentina, seasonal hydrochemical monitoring was carried out between 2013 and 2017. This paper describes underground and surface water flow, and their hydrochemistry, and provides an overview of how groundwater interacts with the rock glacier. The cryogenic basin of the study area where the hydrological

Changes in the frequency and extent of wildfires are expected to lead to substantial and irreversible alterations to permafrost landscapes under a warming climate. Here we review recent publications (2010–2019) that advance our understanding of the effects of wildfire on surface and ground temperatures, on active layer thickness and, where permafrost is ice‐rich, on ground subsidence and the development

Early Holocene winter air temperatures have been reconstructed for the north‐eastern part of the East European Plain using stable isotope (δ18O and δ2H) records of syngenetic ice wedges. We show that ice wedges here actively grew synchronously with accumulation of peatlands in bogged and forested depressions between 10 and 8 cal ka BP, corresponding to the early Holocene Thermal Maximum. The slope

Talik and cryopeg development related to channel migration has been observed in arctic deltas, but our knowledge on the configuration, properties, and rate of freezeback has remained limited. Along a main channel of the Colville River Delta (Alaska), we integrated subsurface data from 79 boreholes with a remote sensing analysis to measure channel changes in 1948–2013. We found that closed taliks occurred

The impact of changes in active‐layer thickness on the depth of pervasive macrofracturing (brecciation) in frost‐susceptible bedrock is unclear but important to understanding its physical properties and geohazard potential. Here we report results from a laboratory experiment to test the hypothesis that active‐layer deepening drives an increase in the depth of brecciation. The experiment simulated active‐layer

Subarctic permafrost peatlands cover extensive areas and store large amounts of soil organic carbon that can be remobilized as active layer deepening and thermokarst formation increase in a future warmer climate. Better knowledge of ground thermal variability within these ecosystems is important for understanding future landscape development and permafrost carbon feedbacks. In a peat plateau complex

We analyze ground temperatures measured daily at depths of 0–10 m in the Nadym region, north‐west Siberia (65°18′N, 72°6′E). Nadym is located within the discontinuous permafrost zone and the forest–tundra transition subzone, thus representing an area threatened by permafrost thawing. Soil comprises a 0.4–1.0‐m‐thick topmost layer of peat with high porosity (~0.9), underlain by layers of mineral soil

No abstract is available for this article.

On August 14 2015 a large debris flow initiated by the occurrence of two slope failures at the front of the Lou rock glacier flooded part of the town of Lanslevillard, France. The present study aims to understand the meteorological and geomorphological context that led to these failures. Investigations were conducted by combining meteorological data, surface movements, and geophysical transects. The

To assess the direct impact of climate change on ice‐wedge (IW) degradation, 16 sites in the Narsajuaq river valley (Nunavik, Canada) that were extensively studied between 1989 and 1991 were revisited in 2016, 2017 and 2018. In total, 109 pits were dug to record soil characteristics and IW shapes and depths. Changes in surface conditions were also noted using side‐by‐side comparisons of recent (2017)

Solifluction is one of the most widespread periglacial processes with low annual movement rates in the range of —millimeters to centimeters. Traditional methods to assess solifluction movement usually have low spatial resolution, which hampers our understanding of spatial movement patterns and the factors controlling them. In this study, we (a) test the applicability of unmanned aerial vehicle (UAV)‐based

Arctic lakes located in permafrost regions are susceptible to catastrophic drainage. In this study, we reconstructed historical lake drainage events on the western Arctic Coastal Plain of Alaska between 1955 and 2017 using USGS topographic maps, historical aerial photography (1955), and Landsat Imagery (ca. 1975, ca. 2000, and annually since 2000). We identified 98 lakes larger than 10 ha that partially

Emerging polar coasts have different geothermal regimes than those in submergence. While the scientific community is mainly concerned with rapidly eroding permafrost coastlines in sedimentary formations where relative sea level is rising, much less research has been dedicated to permafrost dynamics in emergent coastal regions where post‐glacial uplift is ongoing. The eastern Hudson Bay coast of Nunavik

Frost heave is a process coupling heat transfer, water migration, water–ice phase change and deformation. Frost heave forms various landforms, such as frost mounds, ice pitons, sorted polygons and stone circles, and potentially induces a variety of engineering failures, such as building inclination, differential engineering foundation and pavement cracking. To understand the mechanism of frost heave

Unfrozen water content has strong control on the permeability, strength and thermal properties of frozen soil. Several techniques have been used to measure unfrozen water content in frozen soil and many models have been developed for its prediction. However, there has been little investigation on the quantitative analysis of the relationship between pressure and unfrozen water content. With the development

The aim of this work was to assess the biogeochemical role of riparian soils in the High Arctic to determine to what extent these soils may act as sources or sinks of carbon (C) and nitrogen (N). To do so, we compared two riparian areas that varied in riparian vegetation coverage and soil physical perturbation (i.e., thermo‐erosion gully) in NE Greenland (74°N) during late summer. Microbial soil respiration

No abstract is available for this article.

The Special Issue that justifies this Editorial has been designed to commemorate the 25th anniversary of the first Spanish scientific meeting of the International Permafrost Association organized in 1994 in Madrid. This Special Issue, entitled “Permafrost and periglacial processes in mid‐ and low‐latitude mountains regions,” includes nine papers from various mountain regions around the world, such

Outside the Alps, the Sierra Nevada is probably the best studied European massif with respect to its past and current environmental dynamics. A multi‐approach research program started in the early 2000s focused on the monitoring of frozen ground conditions in this National Park. Here, we present data on the thermal state and distribution of permafrost and seasonal frozen ground in different sites across

Understanding the long‐term role of cooling the underlying permafrost of the crushed rock structure embankment (CRSE) along the Qinghai–Xizang Railway (QXR) is crucial for the railway's safe operation. The thermal regime of the permafrost under the CRSE is analyzed here using monitoring data of soil temperature from 2005 to 2015. The results show that the CRSE plays an important long‐term role in cooling

Pedoclimate monitoring in the Central Andes is key to understanding climatic change in arid high‐mountain low‐latitude environments. We carried out a study of the thermal–hydric regimes of three soils along an altitudinal gradient in the Licancabur Volcano, northern Chile. In situ measurements of soil and air temperature and water content were collected over 19 months, via temperature and moisture

The periglacial belt is located in the highest parts of temperate mountains. The balance between mean air and ground temperatures and the presence of water determine the effectiveness of periglacial processes related to permafrost, the active layer or seasonally frozen ground (SFG). This study combines thermal and geomorphological data obtained in four Pyrenean massifs (Infierno‐Argualas, Posets, Maladeta

Relict rock glaciers are widespread in the Cantabrian Mountains, with more than 250 lobate, tongued‐shaped and complex landforms identified. Located mostly within glacial cirques, facing north and northeast, these landforms are indicative of the distribution of ancient permafrost. Macro‐fabric analysis allows us to reconstruct the past dynamics of these landforms. Surface macro‐fabric analysis of 34

Knowledge of the amount of unfrozen water and its migration in permafrost soils is important for understanding physico‐chemical and biological processes. Here, we developed sub‐routines in FREZCHEM and embedded them in the WATEREGO2 soil environmental model to: (a) estimate unfrozen water content under changing soil temperatures and water–ice phase changes; and (b) determine the effects of Van der