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Over the recent years, there have been focused international efforts to coordinate the development and compilation of rock glacier inventories. Nevertheless, in some contexts, identifying and characterizing rock glaciers can be challenging as complex conditions and interactions, such as glacier–rock-glacier interactions, can yield landforms or landform assemblages that are beyond a straightforward interpretation and classification through ordinary visual means alone. To gain a better understanding of the spatial and temporal complexity of the ongoing processes where glacier–permafrost interactions have occurred, the characterization of the subsurface of the Gruben rock glacier and its adjacent complex contact zone with the then more extended Little Ice Age Gruben glacier is quantitatively assessed using a petrophysical joint inversion (PJI) scheme, based on electrical resistivity (ERT) and refraction seismic (RST) data. Surface dynamics are assessed using both in situ and close-range remote sensing techniques to monitor daily and seasonal displacements and to monitor landform-wide surface changes at high spatial resolution, respectively. Both the geophysical and geodetic surveys allowed two zones to be identified: the rock glacier zone and the complex contact zone where both permafrost and embedded surface ice are present. In the complex contact zone extremely high ice contents (estimated up to 85 %) were found. Widespread supersaturated permafrost conditions were found in the rock glacier zone. Surface displacement rates in this zone are typical of permafrost creep behaviour, with a gradual acceleration in late spring and a gradual deceleration in winter. Moreover, the coherent nature of the rock glacier zone surface deformation contrasts with the back-creeping and slightly chaotic surface deformation of the complex contact zone. Favouring a multi-method approach allowed a detailed representation of the spatial distribution of ground ice content and origin, which enabled us to discriminate glacial from periglacial processes as their spatio-temporal patterns of surface change and geophysical signatures are (mostly) different. [ABSTRACT FROM AUTHOR]

Rock glaciers – periglacial landforms commonly found in high-mountain systems – are of significant scientific value for inferring the presence of permafrost, understanding mountain hydrology, and assessing climate impacts on high-mountain environments. However, inventories remain patchy in many alpine regions, and as a result they are poorly understood for some areas of High Mountain Asia such as the Tibetan Plateau. To address this gap, we compiled a comprehensive inventory of rock glaciers for the Tibetan Plateau, i.e., TPRoGI (v1.0), developed using an innovative deep learning method. This inventory consists of a total of 44 273 rock glaciers, covering approximately 6000 km2 , with a mean area of 0.14 km2. They are predominantly situated at elevations ranging from 4000 to 5500 m a.s.l., with a mean of 4729 m a.s.l. They tend to occur on slopes with gradients between 10 and 25°, with a mean of 17.7°. Across the plateau, rock glaciers are widespread in the northwestern and southeastern areas, with dense concentrations in the Western Pamir and Nyainqêntanglha, while they are sparsely distributed in the inner part. Our inventory serves as a benchmark dataset, which will be further maintained and updated in the future. This dataset constitutes a significant contribution towards understanding, future monitoring, and assessment of permafrost on the Tibetan Plateau in the context of climate change. The dataset is available at https://doi.org/10.5281/zenodo.10732042 (Sun et al., 2024a). [ABSTRACT FROM AUTHOR]

Satellite imagery has become a major source for identifying and mapping terrestrial and planetary landforms. However, interpretating landforms and their significance, especially in changing environments, may still be questionable. Consequently, ground truth to check training models, especially in mountainous areas, can be problematic. This paper outlines a decimal format, [dLL], for latitude and longitude geolocation that can be used for model interpretation and validation and in data sets. As data have positions in space and time, [dLL] defined points, as for images, can be associated with metadata as nodes. Together with vertices, metadata nodes help build 'information surfaces' as part of the Digital Earth. This paper examines aspects of the Critical Zone and data integration via the FAIR data principles, data that are; findable, accessible, interoperable and re-usable. Mapping and making inventories of rock glacier landforms are examined in the context of their geomorphic and environmental significance and the need for geolocated ground truth. Terrestrial examination of rock glaciers shows them to be predominantly glacier-derived landforms and not indicators of permafrost. Remote-sensing technologies used to track developing rock glacier surface features show them to be climatically melting glaciers beneath rock debris covers. Distinguishing between glaciers, debris-covered glaciers and rock glaciers over time is a challenge for new remote sensing satellites and technologies and shows the necessity for a common geolocation format to report many Earth surface features. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This note suggests that decimal latitude/longitude [dLL] locations should be used to identify features of interest, landforms, sample and investigations sites, in an 'information landscape' provided by the geomorphological literature. All the information associated with a labelled, or tagged, geolocation should be available for examination as part of information landscapes that can be explored and represented in books, papers and other publications. This note also outlines the 'open' and FAIR data that are findable, accessible, interoperable and reusable and how the principles can be used to better explain landscapes, especially in the mountain landscape domain. Tors and rock glaciers illustrate [dLL] geolocation to identify sites and inform fieldwork and literature searching. Any [dLL]‐specified location is an identifying label, as are names given to landforms and toponyms. Two letters (digraph) are used as landform labels: TO for tors and RG for rock glaciers. Citations, (author–date–title–source) attributions, are also labels. The note shows how these attributions can be linked to [dLL] geolocations specifying locations in time and space and in the literature. The addition of [dLL] will facilitate future literature searches and modelling to explore 'unknowns' in the landscape, and this paper suggests ways in which this can be achieved, including geoheritage and geotourism. [ABSTRACT FROM AUTHOR]

Relict periglacial landforms play an important ecosystem role in mountain regions and are becoming relevant in the global context of climate change. In the eastern region of the North Patagonian Andes, many relict periglacial landforms, such as rock glaciers and solifluction lobes, are distributed in mountain watersheds, including the La Hoya mountain watershed. In this watershed, we analyzed hydrochemistry and macroinvertebrate communities across water sources, associated to different landforms (rock glaciers, solifluction lobes, debris slopes, wet meadows, and the collector stream). The results showed that the highest concentrations of nitrates and soluble reactive phosphorus were registered on springs associated with rock glaciers and solifluction lobes, coincident with low water temperature. Macroinvertebrate taxonomic richness was highest in the collector stream and wet meadows. While rock glaciers and solifluction lobes supported low diversity, their assemblages were unique (highest Local Contribution to Beta Diversity). In summary, rock glaciers and solifluction lobes are the principal nutrient contributors to the La Hoya watershed and provide refuge for unique and potentially cold-adapted macroinvertebrates. Due to ongoing climate change in cold environments, ice glaciers and mountain permafrost may disappear or be reduced. In this context, relict periglacial landforms, such as rock glaciers or solifluction lobes, could act as climate change refugia. This assumption requires support from further research at broader scales; nevertheless, our work suggests that the potential ecological and conservation value of relict periglacial landforms should not be underestimated. [ABSTRACT FROM AUTHOR]

Block streams, also known as stone rivers, are common periglacial landforms in the alpine and subalpine zone of the Balkan Peninsula. These features are especially widely spread in the valleys, slopes and summit of Vitosha Mountain. The presented research aims to estimate the total area of block streams and perform morphometric analysis of these landforms within the basin of Vladayska River. Block streams are digitized man-ually from orthophotographs and topographic maps using GIS software. Morphometric parameters such as area, length, width, elongation ratio and mean elevation are calcu-lated or extracted from a digital elevation model for each polygon. A linear regression test was conducted to evaluate the relationship between morphometric properties. Results indicate a significant correlation between the area and perimeter (R2 = 0.93) and between the length and width (R2 = 0.94) of the block streams. Block streams are present in the elevation range between 1177 and 2244 m, covering a total area of 169.7 ha. The largest ones occupy the area of Zlatnite Mostove and Yurushki Most, as well as the vicinity of Cherni Vrah Peak. Their length varies from 5–6 m up to 2.2 km, while their width changes from a few meters up to 0.6–0.7 km. Comparisons between block streams from different sites within the catchment area yield new insights into the diver-sity of these landforms. Their dimensions and spatial distribution are key to understand-ing the processes of their formation and evolution. [ABSTRACT FROM AUTHOR]

The aim of the study is to reveal geomorphological characteristics and evolution of the periglacial landforms occurred on the summit of the Kaz Dağı (in Turkish) characterised with a specific mountain environment developed under the dry summer subtropical Mediterranean climate. To reach this aim, morphoclimatic processes-characteristics and soil development of the Kaz Dağı district have been evaluated. Kaz Dağı (1774 m a.s.l.), which had been called as the Mount Ida in Greek Mythology, forms a physical geographic border between Çanakkale and Balıkesir provinces. Periglacial landforms consisting of the non-sorted circles including mud circles and stony earth circles, non-sorted steps and cryoturbation terraces and block currents, are found in subalpine vegetation zone at upper boundary of Mount Ida. According to morphogenetic process analysis, on the summit of the Kaz Dağı, the dominant processes are freezing + freezing-thawing in the December-March period, freezing-thawing + weathering in the November and April months, and weat-hering in which frost is not effective in the April-November period. As for pedological processes and mineralogical characteristics of soils formed under the same climatic conditions but on different parent materials of various periglacial landforms, taxonomy of these soils was classified at the Entisol ordo described as young soils. [ABSTRACT FROM AUTHOR]

The transboundary part of the Altai mountains has been investigated. It is established that it is characterized by a set of geomorphological elements due to the altitudinal position, geological structure, neotectonic activity, modern and paleo-climatic conditions, and exogenous relief-forming processes. In the highlands of the Mongolian Altai, landforms associated with the formation, movement, and melting of ice are widespread. The geological activity of glaciers, the work of melt water, and the presence of permafrost give rise to bright forms. The formation of the appearance of mountain landscapes and the transformation of the surface are associated with actively ongoing slope processes: avalanches, mudflows, landslides, and rock falls. It is found that the objects of cryogenic genesis are landforms differing in scale, structure, and location. They include snow–ice and rock–ice formations, solifluction forms, areas with frost mounds (palza), polygonal and structural soils, aufeis, etc. It is concluded that the most representative objects of cryogenic genesis illustrating the geological work of ice are modern glacial complexes, rock glaciers, and rock streams. Glaciers constitute the main element of the high-mountain zone for complex conjugated cryogenic forms. In addition to them, smaller forms stand out, the formation of which is associated with the processes of soil change under the influence of permafrost and gravitational processes. Regularities are observed in the structure and arrangement of the landforms in the alpine zone. On the basis of information from field routes, satellite data interpretation, and the use of GIS capabilities, we have analyzed the distribution of cryogenic landforms. Material is prepared on the basis of working with a digital elevation model. A list (catalog) of natural cryogenic objects of different categories identified within the Altai Tavan Bogd National Park has been compiled. The study confirms that the landforms of the highlands are of interest for further study, the replenishment of the catalog of objects, and the development of thematic tourism. [ABSTRACT FROM AUTHOR]

Viscous flow features in perennially frozen talus/debris called rock glaciers are being systematically inventoried as part of global climate-related monitoring of mountain permafrost. In order to avoid duplication and confusion, guidelines were developed by the International Permafrost Association for discriminating 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 difference between the two phenomena/landforms concern: • tight mechanical coupling of the surface material to the frozen rock-ice mixture in the case of rock glaciers as contrasting with essential non-coupling of debris to 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 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 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, remains of buried surface ice mostly tend to be smaller than the lower size limit of "glaciers" as applied in glacier inventories, and to be far thinner than the permafrost in which they are embedded. [ABSTRACT FROM AUTHOR]

Glacial reworking of large rock avalanche sediment significantly contributes to glacial sediment transfer. This study presents two interaction models, derived from a comprehensive site investigation and numerical simulation, to elucidate the redistribution impact of glaciers on rock avalanche deposits. We examined the landforms of rock avalanche deposits subjected to glacial modification for over 14,000 years in Muztagh Ata, Kashgar, Xinjiang Province, China. To accurately capture the kinematic behavior of the glacier, we integrated the Glen flow law into the discontinuous deformation analysis (DDA) coupled with smoothed particle hydrodynamics (SPH) method. Temperature evolution was also considered as a critical input parameter of our models. We found that the region near the glacier source primarily experienced entrainment, while areas further away were characterized by expansion. Additionally, we systematically investigated the effects of temperature and stress exponent on the viscosity and movement distance of glaciers. Our study is expected to provide some valuable insights into the dynamics of glacier interactions with rock avalanche deposits, thereby enhancing understanding of their combined influence on landscape formation and sediment redistribution. [ABSTRACT FROM AUTHOR]

Due to the ongoing degradation of permafrost and the associated impacts on the stability of periglacial mountain slopes, there is a need to improve our understanding of the dynamics of rock glaciers over relatively short timescales. There is also a growing interest in the hydrological role of rock glaciers and other ice-debris landforms, as they can potentially store valuable amounts of ice. Despite the acceleration in rock glacier velocities observed primarily in the European Alps, annual and inter-annual changes in surface elevation and volume have so far escaped detailed quantification in monitoring programs. In this study, annual and biannual uncrewed aerial vehicle (UAV) surveys combined with structure-from-motion (SfM) photogrammetric techniques are used to derive high-resolution surface kinematics, elevation and volume changes of three rock glaciers in the Western Swiss Alps. Between 2016 and 2021, detailed digital elevation model (DEM) differencing revealed a high variability of mean annual elevation changes, reaching up to −0.19 ± 0.02 m/yr (2020−2021) at the Yettes Condjà B rock glacier, while elevation changes at the Les Cliosses rock glacier ranged from −0.05 ± 0.02 m/yr (2016–2017) to +0.014 ± 0.008 m/yr (2021−2021). In addition, the multi-temporal and very high-resolution topographic datasets revealed the presence of distinct rock glacier features, including superimposed lobes, lateral levees and flow divides, that could not be identified previously with traditional in-situ measurements and observations. Our results in terms of elevation and surface velocity changes highlight the importance of detailed and regular high-resolution monitoring for understanding the rapid evolution of active glaciers under the current degradation of mountain permafrost. • Centimetre-scale DEMs and orthomosaics are derived from UAV surveys. • Elevation changes range from −0.19 ± 0.02 m/yr to +0.014 ± 0.008 m/yr. • Short-term volume changes indicate a complex mass redistribution. • Annual elevation changes a novel complement to the study of rock glacier dynamics. [ABSTRACT FROM AUTHOR]

The search for past and present water on Mars, either as liquid or solid ice, with its important climatological and astrobiological consequences, has been bolstered by novel techniques, and from the release of recent imagery. Although ice is more frequently observed at higher latitudes, evidence of ice and water-related deposits and erosional features has also been identified at equatorial latitudes. This work focuses on the evidence for ancient ice and water-related features in Valles Marineris, Mars' most extensive canyon system, particularly in its deepest southeastern section, Coprates Chasma. We first consider existing information on water, glacial, and periglacial landforms and introduce new findings and imagery based on orbiters and on physical considerations. We examine the peculiar morphologies of two major landslides in Coprates Chasma, which can potentially imply icy conditions at the chasm's base. Analogies to Earth's glacially-induced landslides could hint at similar dynamics and the presence of ice within Valles Marineris. Remarkably intact landforms in Coprates Chasma include pitted cones remnants, commonly deduced to be volcanic cinder cones or mud volcanoes, and here interpreted as landforms more similar to pingos or hydrolaccolites, and then protalus ramparts, ice-affected impact craters, kettle holes from ice melt or sublimation, alases, and rock glaciers. The fluted terrain at the forefront of the Coprates Labes landslide indicate the presence of running water at the bottom of Coprates Chasma about 3 Ga ago. A 20-km long feature, here nicknamed the "Ghost Glacier", characterized by thin sub-parallel grooves, is interpreted as the remnant of a series of drop moraines abandoned by a local cold-based glacier, possibly one of the Valles Marineris' (Magnarini et al., 2019) oldest identifiable features. By examining the contacts between landslide deposits and the terrain of stacked landslide sequences, including craters underneath a landslide body, we deduce that ice in Valles Marineris was present as permafrost or in thin bodies growing locally to at most some meters in thickness. Moreover, the longitudinal profile indicates the lack of a thick glacier within the main valley. We conclude that the past occurrence of glacialism in Valles Marineris was only partly suggestive of glacial conditions found in Earth's Alpine valleys. Additionally, imagery corroborates the existence of a regolith-veneered lacustrine surface, dated to a recent age of 1.1 Ga, over which a massive landslide slid. We propose a tentative hydrological-glaciological history of Coprates Chasma, grounded in published research and our findings. • Coprates Chasma is an eastern chasm of Valles Marineris on Mars, where water ponded in a vast lake. • Torrential, glacial, periglacial landforms, and landslide deposits within Coprates Chasma are reviewed. • New observations and age assessments are provided for some key morphologies and terrains. • The glacial-periglacial history of this area is tentatively reconstructed. [ABSTRACT FROM AUTHOR]

Schmidt-hammer exposure-age dating (SHD) was used to evaluate the surface age, dynamics and evolution of eight talus (scree) slopes located between ~520 and ~1010 m a.s.l. in the upper Jostedalen area of southern Norway. Statistically significant differences in mean R-values were found between talus slopes but there was no consistent difference in R-values between three mid- to lower-slope positions, two operators, or first and second impacts from the same boulders. A new regional age-calibration equation yielded SHD ages ranging from 8425 ± 700 years to 2620 ± 740 years. SHD ages from talus slopes and other landforms with diachronous surfaces (such as alluvial fans, snow-avalanche fans, pronival ramparts and rock glaciers) represent the average exposure age of the surface boulders and provide insights into landform evolution. Here, our SHD ages are interpreted in terms of Early Holocene paraglacial rock-slope instability, Mid-Holocene permafrost degradation, low but possibly variable rates of rockfall activity in the Late-Holocene, and spatial variations affected by local site differences. Survival of rock particles with relatively old exposure ages towards the distal margins of the talus slopes is attributed to their slow development with low levels of modern activity. SHD ages from diachronous surfaces may considerably underestimate landform age (defined as the onset of landform formation). Greater application can be anticipated, however, in the inference of landform dynamics from the R-value distributions of diachronous surfaces and in the use of SHD age as an indicator of the extent of modern activity. [ABSTRACT FROM AUTHOR]

The cold climate events of the Upper Cenozoic greatly modified the landscape of Patagonia, where a large number of relicts and active landforms of glacial, periglacial and paraglacial origin is preserved. To assess the regional paleoclimatic record when numerical ages are unavailable, the spatial distribution of local depositional landform sequences was analyzed in six mountain ranges located on the eastern margin of the North Patagonian Andes. The analysis of satellite images and digital elevation model, fieldwork research and its integration into a Geographical Information System were used to develop a detailed inventory of mountain landforms. A total of 67 glacial valleys, 97 glacial cirques, 94 moraines, 75 rock glaciers, 103 protalus ramparts, and more than 145 km2 and 100 km2 of surface affected by solifluction and mass wasting processes respectively were mapped. From the analysis of the spatial and altitudinal distribution of landforms, we defined temporal and spatial sequences of morpho-climate importance. We recognized four major morpho-climate events associated with local paleoclimate conditions and one stage of a recent paraglacial adjustment. The oldest cold climate event recognized might be correlated with the Last Glacial Maximum. The results show the rise in the average air temperature and an aridity trend for the study area since the Late Pleistocene. During this lapse, glacial environments evolved to periglacial environments, although was recognized their coexistence in some areas in the same mountain range. • Eastern North Patagonian Andes preserve numerous glacial and periglacial landforms. • Glacial and periglacial landforms reveal four major cold climate events. • Landform sequences show a transition between glacial and periglacial environments. • The oldest event may be correlated with the Last Glacial Maximum (LGM). • The youngest event might be linked to the Little Ice Age (LIA). [ABSTRACT FROM AUTHOR]

In this study, we inventoried and mapped the active and transitional rock glaciers in the central part of the Southern Alps, New Zealand, using Sentinel-1 InSAR (interferometric synthetic aperture radar) data. We used forty-three interferograms acquired between 2015 and 2019 with time intervals between six days and two years along with orthoimage analyses. A total of 123 rock glaciers were identified, of which 40 are active; that is, displaying velocities higher than 10 cm/yr. The remaining landforms are considered transitional. Among the complete sample of rock glaciers inventoried, 9 may also be interpreted as debris-covered glacierets. The number of inventoried landforms is low compared to what is observed in other similar mountain ranges, such as the European Alps. We explain this by the reduced vertical extent of the periglacial belt and the generally steep topography often not favorable for rock glacier development. Additionally, the motion rates appear relatively low. We hypothesize that a mean annual air temperature at the rock glacier locations well above 0°C is the main reason for this. These conditions may have resulted in significant ground ice melt. Rock glaciers in the Southern Alps are thus in an inactivation phase, which is expressed by typical morphologies such as stable fronts. [ABSTRACT FROM AUTHOR]

Intact rock glaciers are common periglacial landforms that occur in cold alpine mountains and are often considered indicators of alpine permafrost. They can be both active and inactive, but both have ice in them and can be hydrologically significant. Little is known about the distribution of the rock glaciers in the Himalaya at basin-scale and content of water that can be hydrologically significant during the water-stressed months. We have found 967 intact rock glaciers covering an area of 306 km2 in the river basins of Beas, Chenab, Ravi, Sutlej, and Yamuna. Out of these, around 77% are moraine derived and the rest are talus derived. Most of them occur in the elevation between 4000 and 4500 m having a slope of 10° to 30° with a westerly and south-westerly aspect. They start occurring from 3220 to 6206 m, in places with −10°C to 10°C mean monthly temperature and within 50–100 cm of average monthly precipitation. Their alignment suggests that these rock glaciers occur in the area with low to medium incoming solar radiations. These rock glaciers are generally found where the general rock types are low-grade metamorphic rocks and feldspar-rich intrusive granites occurring beyond the Main Central Thrust in the Higher Himalaya. Finally, we calculated about 8.5 billion m3 volume of water (ice water equivalent) stored in them, considering 60% of the volume of rock glaciers is ice. [ABSTRACT FROM AUTHOR]

The detailed description of processing workflows in Structure from Motion (SfM) surveys using unmanned aerial vehicles (UAVs) is not common in geomorphological research. One of the aspects frequently overlooked in photogrammetric reconstruction is image characteristics. In this context, the present study aims to determine whether the format or properties (e.g., exposure, sharpening, lens corrections) of the images used in the SfM process can affect high-detail surveys of complex geometric landforms such as rock glaciers. For this purpose, images generated (DNG and JPEG) and derived (TIFF) from low-cost UAV systems widely used by the scientific community are applied. The case study is carried out through a comprehensive flight plan with ground control and differences among surveys are assessed visually and geometrically. Thus, geometric evaluation is based on 2.5D and 3D perspectives and a ground-based LiDAR benchmark. The results show that the lens profiles applied by some low-cost UAV cameras to the images can significantly alter the geometry among photo-reconstructions, to the extent that they can influence monitoring activities with variations of around ±5 cm in areas with close control and over ±20 cm (10 times the ground sample distance) on surfaces outside the ground control surroundings. The terrestrial position of the laser scanner measurements and the scene changing topography results in uneven surface sampling, which makes it challenging to determine which set of images best fit the LiDAR benchmark. Other effects of the image properties are found in minor variations scattered throughout the survey or modifications to the RGB values of the point clouds or orthomosaics, with no critical impact on geomorphological studies. [ABSTRACT FROM AUTHOR]

Mountains are global biodiversity hotspots where cold environments and their associated ecological communities are threatened by climate warming. Considerable research attention has been devoted to understanding the ecological effects of alpine glacier and snowfield recession. However, much less attention has been given to identifying climate refugia in mountain ecosystems where present‐day environmental conditions will be maintained, at least in the near‐term, as other habitats change. Around the world, montane communities of microbes, animals, and plants live on, adjacent to, and downstream of rock glaciers and related cold rocky landforms (CRL). These geomorphological features have been overlooked in the ecological literature despite being extremely common in mountain ranges worldwide with a propensity to support cold and stable habitats for aquatic and terrestrial biodiversity. CRLs are less responsive to atmospheric warming than alpine glaciers and snowfields due to the insulating nature and thermal inertia of their debris cover paired with their internal ventilation patterns. Thus, CRLs are likely to remain on the landscape after adjacent glaciers and snowfields have melted, thereby providing longer‐term cold habitat for biodiversity living on and downstream of them. Here, we show that CRLs will likely act as key climate refugia for terrestrial and aquatic biodiversity in mountain ecosystems, offer guidelines for incorporating CRLs into conservation practices, and identify areas for future research. [ABSTRACT FROM AUTHOR]

Mechanical processes operating on the slope surface or at depth control the dynamics of alpine landforms and hold critical information of their geomorphological characteristics, yet they often lack systematic quantification and in‐depth interpretation. This study aims to address a long‐standing issue concerning geomorphological classification from a kinematic perspective. A group of periglacial landforms consisting of several lobes were discovered in the East Kunlun Mountains of China 30 years ago but were ambiguously classified as rock glaciers and later as gelifluction deposits. Here, we use satellite Interferometric Synthetic Aperture Radar to quantitatively characterize the spatial and temporal changes of the surface movement of these landforms. We observe that: (1) its 17 lobes show a pattern of landform‐scale and uniform surface movement, especially during May to October; (2) the lobes move at a spatial mean downslope velocity of 10 to 60 cm/yr and a maximum velocity as high as 100 cm/yr in summer; (3) the landforms are nearly inactive from winter to late spring. Based on these observations, we postulate that the movement of the lobes are driven by deep‐seated permafrost creep which typically occurs in rock glaciers. The debris of Lobe No.4 is composed of both boulders and pebbles supported by fine‐grained matrix generated from the in situ weathering process. It develops a talus‐like oversteepened front around 40° and a convex transverse profile perpendicular to the creep direction, which are also characteristic features of a rock glacier. Piecing these observations together, we identify Lobe No.4 as a debris‐mantled‐slope‐connected rock glacier, with the gelifluction process occurring on the surface as small‐scale and discrete events. © 2020 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Copyright of Cuadernos de Investigación Geográfica is the property of Universidad de la Rioja, Servicio de Publicaciones and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Cuadernos de Investigación Geográfica is the property of Universidad de la Rioja, Servicio de Publicaciones and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Abstract Block streams, as common features in the Southern Carpathians, are essential for understanding the evolution of alpine environments. Despite their widespread occurrence, they have frequently been omitted from previous inventories of periglacial landforms and from the general understanding of landscape development. This study evaluated the environmental controls on spatial distribution and dimensions of 2056 block streams for a better understanding of their evolution and climatic significance. Different lithology classes and topographic characteristics were assessed using standard least-square linear regression and one-way analysis of variance (ANOVA). The majority of the block streams belong to the linear morphological type, but six other types of morphologies were found (e.g. sinuous, curved, and braided). Bivariate and multivariate statistical analysis revealed a high density of landforms on southern slopes (59%), granite terrains (47%), and above 1750 m. Large features occur mainly on southern slopes and in areas with granites. Landform dimensions and spatial distribution are influenced to a certain degree by lithology, slope aspect, and elevation, making it difficult to identify a dominant factor. Block streams developed extensively at the end of the Pleistocene under permafrost conditions. Today, these features suggest inactivity, but during the cool episodes of the Holocene (e.g. Little Ice Age - LIA), the formation of block streams above 2100 m was re-initiated. Future absolute dating and monitoring of landform dynamics will support these findings. Graphical abstract Unlabelled Image Highlights • 2056 block streams were mapped in the Retezat-Godeanu Mountains. • The highest number of landforms occurred on granites and on southern slopes. • Seven different morphological typologies of block streams were identified. • Lithology played a significant role in controlling landform size. • Several generations of features are related to varied stages of permafrost formation. [ABSTRACT FROM AUTHOR]

Rock glaciers in semiarid mountains contain large amounts of ice and might be important water stores aside from glaciers, lakes, and rivers. Yet whether and how rock glaciers interact with river channels in mountain valleys remains largely unresolved. We examine the potential for rock glaciers to block or disrupt river channels, using a new inventory of more than 2000 intact rock glaciers that we mapped from remotely sensed imagery in the Karakoram (KR), Tien Shan (TS), and Altai (ALT) mountains. We find that between 5% and 14% of the rock glaciers partly buried, blocked, diverted or constricted at least 95 km of mountain rivers in the entire study area. We use a Bayesian robust logistic regression with multiple topographic and climatic inputs to discern those rock glaciers disrupting mountain rivers from those with no obvious impacts. We identify elevation and potential incoming solar radiation (PISR), together with the size of feeder basins, as dominant predictors, so that lower‐lying and larger rock glaciers from larger basins are more likely to disrupt river channels. Given that elevation and PISR are key inputs for modelling the regional distribution of mountain permafrost from the positions of rock‐glacier toes, we infer that river‐blocking rock glaciers may be diagnostic of non‐equilibrated permafrost. Principal component analysis adds temperature evenness and wet‐season precipitation to the controls that characterise rock glaciers impacting on rivers. Depending on the choice of predictors, the accuracy of our classification is moderate to good with median posterior area‐under‐the‐curve values of 0.71–0.89. Clarifying whether rapidly advancing rock glaciers can physically impound rivers, or fortify existing dams instead, deserves future field investigation. We suspect that rock‐glacier dams are conspicuous features that have a polygenetic history and encourage more research on the geomorphic coupling between permafrost lobes, river channels, and the sediment cascades of semiarid mountain belts. © 2018 John Wiley & Sons, Ltd. We examine the potential for rock glaciers to block or disrupt river channels, using a new inventory of more than 2000 intact rock glaciers in the Karakoram, Tien Shan, and Altai mountains. We find that between 5% and 14% of these rock glaciers buried, blocked, diverted or constricted at least 95 km of mountain rivers in the entire study area, completely disrupting or at least partly disturbing the sediment delivery from as much as 3600 km2. [ABSTRACT FROM AUTHOR]

When connected to torrential channels, periglacial moving landforms (including rock glaciers, push moraines and high-altitude landsliding masses) may constitute important active sediment sources for gravitational and torrential transfer processes such as debris flows. However, still very little is known about the location and the number of such types of sedimentary connection in given regions, as well as about the typical sediment transfer rates that can be expected. Therefore, this contribution aims at (i) describing a new methodology developed to identify and characterize moving landforms connected to the torrential network system at a regional scale and (ii) presenting the results yielded from the application of this method in a 2000 km 2 region in the southwestern Swiss Alps. The developed approach is based on the analysis of simple data such as a high-resolution digital elevation model (DEM), time series of aerial images and a slope movement inventory. The approach allowed both the fast identification of moving landforms connected to torrential channels and the estimation of annual sediment transfer rates for these inventoried landforms. In the study region, results showed that such types of sedimentary connection appeared to be rather rare. Results also showed that most connected moving landforms were characterized by relatively low sediment transfer rates (<500 m 3 yr -1) but several sites were identified as transferring large amounts of sediment into the torrents (>1000 m 3 yr -1). As sediment transfer rates depend on the kinematical behavior of the landforms, values calculated may change in regard to the evolution of the surface velocities, which are currently generally increasing in the European Alps. When connected to torrents, periglacial moving landforms may thus represent substantial active sources of sediments for the development of debris flows and should be considered in the management of torrential catchments. [ABSTRACT FROM AUTHOR]

In the Nepalese Himalaya, there is little information on the number, spatial distribution and morphometric characteristics of rock glaciers, and this information is required if their hydrological contribution is to be understood. Based on freely available fine spatial resolution satellite data accessible through Google Earth, we produced the first comprehensive Nepalese rock glacier inventory, supported through statistical validation and field survey. The inventory includes the location of over 6000 rock glaciers, with a mean specific density of 3.4%. This corresponds to an areal coverage of 1371 km 2 . Our approach subsampled approximately 20% of the total identified rock glacier inventory ( n = 1137) and digitised their outlines so that quantitative/qualitative landform attributes could be extracted. Intact landforms (containing ice) accounted for 68% of the subsample, and the remaining were classified as relict (not containing ice). The majority (56%) were found to have a northerly aspect (NE, N, and NW), and landforms situated within north- to west-aspects reside at lower elevations than those with south- to- east aspects. In Nepal, we show that rock glaciers are situated between 3225 and 5675 m a.s.l., with the mean minimum elevation at the front estimated to be 4977 ± 280 m a.s.l. for intact landforms and 4541 ± 346 m a.s.l. for relict landforms. The hydrological significance of rock glaciers in Nepal was then established by statistically upscaling the results from the subsample to estimate that these cryospheric reserves store between 16.72 and 25.08 billion m 3 of water. This study, for the first time, estimates rock glacier water volume equivalents and evaluates their relative hydrological importance in comparison to ice glaciers. Across the Nepalese Himalaya, rock glacier to ice glacier water volume equivalent is 1:9, and generally increases westwards (e.g., ratio = 1:3, West region). This inventory represents a preliminary step for understanding the spatial distribution and the geomorphic conditions necessary for rock glacier formation in the Himalaya. With continued climatically-driven ice glacier recession, the relative importance of rock glaciers in the Nepalese Himalaya will potentially increase. [ABSTRACT FROM AUTHOR]

The thermal regimes of alpine streams remain understudied and have important implications for cold-water fish habitat, which is expected to decline due to climatic warming. Previous research has focused on the effects of distributed energy fluxes and meltwater from snowpacks and glaciers on the temperature of mountain streams. This study presents the effects of the groundwater spring discharge from an inactive rock glacier containing little ground ice on the temperature of an alpine stream. Rock glaciers are coarse blocky landforms that are ubiquitous in alpine environments and typically exhibit low groundwater discharge temperatures and resilience to climatic warming. Water temperature data indicate that the rock glacier spring cools the stream by an average of 3 °C during July and August and reduces maximum daily temperatures by an average of 5 °C during the peak temperature period of the first two weeks in August, producing a cold-water refuge downstream of the spring. The distributed stream surface and streambed energy fluxes are calculated for the reach along the toe of the rock glacier, and solar radiation dominates the distributed stream energy budget. The lateral advective heat flux generated by the rock glacier spring is compared to the distributed energy fluxes over the study reach, and the spring advective heat flux is the dominant control on stream temperature at the reach scale. This study highlights the potential for coarse blocky landforms to generate climatically resilient cold-water refuges in alpine streams. [ABSTRACT FROM AUTHOR]

Identification of bouldery landforms in mountains and correctly understanding their formative processes play an important role in reconstructing the geomorphic history of a region. We propose that blocks were liberated by frost cracking and wedging of cliff walls during the last glacial period. However, we further suggest and test four hypotheses comprising different scenarios for preconditioning by chemical weathering and subsequent block transport using terrain analysis, characterization of boulders, and 10Be exposure dating. Frost shattering from the backing cliff produced the boulders since the beginning of the last glacial period (~80 ka), and gelifluction transported them downslope throughout the last glacial period. Their activity then entered a dormant phase at the beginning of the Holocene. Distribution patterns of exposure ages of tors and block streams are similar to those of previous studies, implying that bouldery landscapes in the southern Korean Peninsula were likely to be formed by similar processes under periglacial conditions. The timing of active periods in transport of block streams corresponds well with the cold periods identified in regional and global climate proxy records. Interestingly, the activity of block streams in the study area reached a maximum during Marine Oxygen Isotope Stage 3 to 2 when the growth rate of nearby speleothems was lowest. [ABSTRACT FROM PUBLISHER]

The paper aims to determine to what extent the size of the rock glaciers (RG) in the Southern Carpathians (Romania) is influenced by their contributing area (CA) parameters. Simple linear regression (LR) and generalized linear models (GLM) were used to meet this goal, considering as independent variables the main morphometric characteristics of the contributing area. The LR coefficients revealed that the most influential variables were the width (R2=0.57) and the size of the CA (R2=0.51). Based on the best GLM results the size of the rock glaciers can be statistically explained quite well (R2=0.58) by a combination of three variables: CA length, CA width, and the minimum altitude of the CA. Rock glaciers are thus complex landforms resulting from a combination of many variables (climatic, topographic and geologic) including contributing area parameters. Both LR and GLM analysis revealed that the size of the rock glaciers can only be partly explained by the characteristics of the CA. The study revealed that GLM are powerful analytical tools which give reasonable results when analysing the role of rock glaciers developmental controls. [ABSTRACT FROM AUTHOR]

Active rock glaciers are periglacial landforms consisting of coarse debris with interstitial ice or ice-core. Recent studies showed that such landforms are able to support plant and arthropod life and could act as warm-stage refugia for cold-adapted species due to their microclimate features and thermal inertia. However, integrated research comparing active rock glaciers with surrounding landforms to outline their ecological peculiarities is still scarce. We analysed the abiotic (ground surface temperature and humidity, soil physical and chemical parameters) and biotic (plant and arthropod communities) features of two Alpine active rock glaciers with contrasting lithology (silicate and carbonate), and compared them with the surrounding iceless landforms as reference sites (stable slopes and active scree slopes). Our data show remarkable differences between stable slopes and unstable landforms as a whole, while few differences occur between active scree slopes and active rock glaciers: such landforms show similar soil features but different ground surface temperatures (lower on active rock glaciers) and different occurrence of cold-adapted species (more frequent/abundant on active rock glaciers). Both plant and arthropod species distributions depend mainly on the geographical context as a function of soil pH and on the contrast between stable slopes and unstable landforms as a function of the coarse debris fraction and organic matter content, while the few differences between active scree slopes and active rock glaciers can probably be attributed to microclimate. The role of active rock glaciers as potential warm-stage refugia for cold-adapted species is supported by our data; however, at least in the European Alps, their role in this may be less important than that of debris-covered glaciers, which are able to host cold-adapted species even below the climatic tree line. [ABSTRACT FROM AUTHOR]

Interactions between different formative processes are reflected in the internal structure of rock glaciers. Therefore, the detection of subsurface conditions can help to enhance our understanding of landform development. For an assessment of subsurface conditions, we present an analysis of the spatial variability of active layer thickness, ground ice content and frost table topography for two different rock glaciers in the Eastern Swiss Alps by means of quasi-3-D electrical resistivity imaging (ERI). This approach enables an extensive mapping of subsurface structures and a spatial overlay between site-specific surface and subsurface characteristics. At Nair rock glacier, we discovered a gradual descent of the frost table in a downslope direction and a constant decrease of ice content which follows the observed surface topography. This is attributed to ice formation by refreezing meltwater from an embedded snow bank or from a subsurface ice patch which reshapes the permafrost layer. The heterogeneous ground ice distribution at Uertsch rock glacier indicates that multiple processes on different time domains were involved in the development. Resistivity values which represent frozen conditions vary within a wide range and indicate a successive formation which includes several advances, past glacial overrides and creep processes on the rock glacier surface. In combination with the observed topography, quasi-3-D ERI enables us to delimit areas of extensive and compressive flow in close proximity. Excellent data quality was provided by a good coupling of electrodes to the ground in the pebbly material of the investigated rock glaciers. Results show the value of the quasi-3-D ERI approach but advise the application of complementary geophysical methods for interpreting the results. [ABSTRACT FROM AUTHOR]

Pit craters are circular to subcircular depressions that lack a rim and ejecta layer and typically have a conical shape. There are several mechanisms that can explain the formation of such depressions and they are associated with collapse due to the removal of subsurface material. Possible origins of pit craters include: volcanic processes (collapse of lava tubes, magmatic chambers, intrusion of dikes), karstic dissolution, extensional faulting or volatile processes. In this work, we study pit craters in the north-estern external slope of Hale Crater. We identified >40 pit craters that present unique morphological features in association with different landforms associated with volatile activity in the area. We identified moraine like ridges, gullies and aprons together with pits that represent an interesting suite of landforms. After producing a detailed geomorphic map, we classified the pits into: i) single pit craters, ii) chain pit craters, iii) complex pit craters and iv) elongated pit craters. We used DTMs to determine orientation and slopes of the pit craters-hosting terrains and to analyze elevation profiles of the different types of pits and their relation with the gullies and other features. In addition, we performed a spectral analysis using CRISM multispectral dataset in order to characterize the mineralogy of the sediments in the region and to identify any distinctive properties that could promote the formation of these depressions. Here, we propose that pit craters are stratigraphically on top of the ice-related landforms and present complex relationships with the gullies. The spatial relationship between the pits and these structures, along with the absence of evidence of present or past volcanic activity and the lack of evidence of any extensional faulting allows us to propose that the origin of the pit craters in the study area might be related to some volatile process. We propose here that these particular pit craters at Hale crater, are morphologically similar to Icelandic depressions located in a glacial environment. We conclude that the landforms found in the area are in close relation with glacial or periglacial conditions and pit craters might be formed by sublimation/melting of ground ice. • Identification and morphological description of pit craters in Hale Crater. • Association of pit craters with rock glaciers, moraines and gullies. • Iceland as a potential analogue of sublimation pit craters. • Evolution history from single to complex pits. • Sublimation processes leading to collapse and pit crater formation. [ABSTRACT FROM AUTHOR]

On the northern coast of the Hornsund fjord at SW Svalbard, numerous rock block accumulations flank the foot of Rotjesfjellet ridge. Whereas these accumulations are widely described as rock glaciers, this study shows that other factors also influence formation of these landforms. In this study, morphometric profiling and terrain analyses, lichenometry, optical granulometry, Schmidt hammer measurements, geophysical measurements using electric resistivity tomography, geodetic measurements using terrestrial LiDAR and rockfall modelling were used to clarify the formation of one unusual block accumulation. The morphometric analysis of a detailed (0.5 m) DEM and relief profiles showed distinctly different morphology of one of four studied block accumulations. The electric resistivity tomography revealed an ice core in the accumulation, the Schmidt hammer sampling helped to establish relatively younger age of the lobe-like left part of accumulation and finally, the lichenometry was employed to place the event on the approximate position on the timescale. In conclusion, the unusual block accumulation is a result of two consequent processes: first, a typical foothill rock glacier has developed, and consequently a large rock avalanche occurred, adding material and deforming the NW part of the accumulation. Based on the results of lichenometry, the rock avalanche was estimated to be 250 ± 50 years old. The study thus presents one of the few reported slope deformation events from the recently deglaciated Arctic areas. [ABSTRACT FROM AUTHOR]

Rock glaciers are landforms that form as a result of creeping mountain permafrost which have received considerable attention concerning their dynamical and thermal changes. Observed changes in rock glacier motion on seasonal to decadal timescales have been linked to ground temperature variations and related changes in landform geometries interpreted as signs of degradation due to climate warming. Despite the extensive kinematic and thermal monitoring of these creeping permafrost landforms, our understanding of the controlling factors remains limited and lacks robust quantitative models of rock glacier evolution in relation to their environmental setting. Here, we use a holistic approach to analyze the current and long-term dynamical development of two rock glaciers in the Swiss Alps. Site-specific sedimentation and ice generation rates are linked with an adapted numerical flow model for rock glaciers that couples the process chain from material deposition to rock glacier flow in order to reproduce observed rock glacier geometries and their general dynamics. Modeling experiments exploring the impact of variations in rock glacier temperature and sediment-ice supply show that these forcing processes are not sufficient to explain the currently observed short-term geometrical changes derived from multitemporal digital terrain models at the two different rock glaciers. The modeling also shows that rock glacier thickness is dominantly controlled by slope and rheology while the advance rates are mostly constrained by rates of sediment-ice supply. Furthermore, timescales of dynamical adjustment are found to be strongly linked to creep velocity. Overall, we provide a useful modeling framework for a better understanding of the dynamical response and morphological changes of rock glaciers to changes in external forcing. [ABSTRACT FROM AUTHOR]

Rock glaciers and protalus ramparts are characteristic landforms of the periglacial domain often used as markers for the occurrence of permafrost in mountain terrains. As such, relict rock glaciers can be used for paleoclimate reconstructions. We present here the first previously unreported rock glacier inventory of the south-eastern Alps (including the north-eastern-most region of Italy and Slovenia), interpreted from high resolution orthophotos and a high resolution digital terrain model interpolated from airborne laser scanning (LiDAR). We mapped 53 rock glaciers covering a total area of 3.45 km 2 . The majority of rock glaciers are classified as relict and distributed between 1708 and 1846 m a.s.l. with slope ranging between 19° and 27°. In addition to rock glaciers we observed 66 protalus (pronival) ramparts, having median elevation of 1913 m a.s.l. and covering 0.48 km 2 . More than half of the inventoried protalus ramparts are located in the more maritime area of the Alps with higher precipitation compared to the location of rock glaciers. Using paleoclimate reconstruction based on the 1981–2010 climatological record of the area, we infer that the rock glaciers formed during one of the dry and cold periods of the late Pleistocene and early Holocene. Possible evolution of the active pronival forms observed in the most maritime area of this alpine sector is also discussed. [ABSTRACT FROM AUTHOR]

Active periglacial processes are currently marginal in the Iberian Peninsula, spatially limited to the highest mountain ranges. However, a wide variety of periglacial deposits and landforms are distributed in low and mid-altitude environments, which shows evidence of past periods of enhanced periglacial activity. The purpose of this paper is to summarize the present knowledge of past periglacial activity in the Iberian Peninsula. The chronological framework takes four main stages into account: the last glaciation, deglaciation, Holocene and present-day processes. This study focuses on the highest massifs (Pyrenees, Cantabrian Range, NW ranges, Central Range, Iberian Range, Sierra Nevada) as well as other lower elevation environments, namely the central Iberian Meseta. During the last glaciation the periglacial belt extended to much lower altitudes than today, reaching current sea level in the NW corner of the Iberian Peninsula. A wide range of geomorphological landforms and sedimentary records is indicative of very active periglacial processes during that phase, in some cases related to permafrost conditions (i.e., block streams, rock glaciers). Most of the inactive landforms and deposits in low and mid-elevations in Iberia are also related to this phase. The massive deglaciation of the Iberian massifs was caused by a gradual increase in temperatures. The deglaciation phase was only interrupted by a short period with colder conditions (the Younger Dryas) that reactivated periglacial processes in the formerly glaciated cirques of the highest lands, specifically with the widespread development of rock glaciers. During the Holocene, periglacial processes have been only active in the highest ranges, shifting in altitude according to temperature regimes and moisture conditions. The Little Ice Age saw the reactivation of periglacial activity in lower elevations than today. Currently, periglacial processes are only active in elevations exceeding 2500 m in the southern ranges and above 2000–2200 m in the northern massifs, higher in Sierra Nevada, in the south of Iberian Peninsula. [ABSTRACT FROM AUTHOR]

ABSTRACT Surface temperature increases since the 1990s have often been associated with an increase in the speed of rock glaciers. Evidence of similar links on the centennial to millennial scale are, however, still lacking due to less focus to date on the medium- and long-term kinematics of these landforms. In order to assess (palaeo)climatic variations in rock glacier kinematics, we analysed the movements of the Stabbio di Largario rock glacier in the southern Swiss Alps using three different timescales. The Schmidt hammer exposure-age dating (SHD) was applied to study long-term kinematics in order to extrapolate the minimal age of the formation of the rock glacier, which may have started its development after the Mid-Holocene climate optimum, and to detect possible accelerations of the horizontal surface velocity during the Medieval Warm Period. Georeferentiation and orthorectification of six historical photographs of the rock glacier taken between ad 1910 and today were analysed using monoplotting to detect the rock glacier displacement on the decennial scale from the end of the Little Ice Age. Finally, differential global positioning system (dGPS) monitoring data available since ad 2009 were used to assess annual and seasonal creep rates of the rock glacier at present. Our results show a link between the periods of increase in mean air temperature on different timescales and variations in rock glacier kinematics and provide important new insights into rock glacier development and evolution on the long-term scale. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: Rock glaciers contain valuable information about the spatial and temporal distribution of permafrost. The wide distribution of these landforms in high mountains promotes them as useful archives for the deciphering of the environmental conditions during their formation and evolution. However, age constraints are needed to unravel the palaeoclimatic context of rock glaciers, but numerical dating is difficult. Here, we present a case study assessing the potential of luminescence techniques (OSL, IRSL) to date the inner sand-rich layer of active rock glaciers. We focus on the signal properties and the resetting of the signal prior to deposition by investigating single grains. While most quartz shows low signal intensities and problematic luminescence characteristics, K-feldspar exhibits much brighter and well-performing signals. Most signals from plagioclases do not show suitable properties. Luminescence signals far below saturation indicate distinct but differential bleaching. The finite mixture model was used to determine the prominent populations in the equivalent dose distributions. The luminescence ages represent travel times of grains since incorporation into the rock glacier and hence, minimum ages of rock glacier formation. Luminescence ages between 3 ka and 8 ka for three rock glaciers from the Upper Engadine and Albula region (Swiss Alps) agree well with independent age estimates from relative and semi-quantitative approaches. Therefore, luminescence seems to have the potential of revealing age constraints about processes related to the formation of rock glaciers, but further investigations are required for solving some of the problems remaining and reducing the dating uncertainties. [Copyright &y& Elsevier]

To explore thermal regimes and hydrologic capacity of rock glaciers and related periglacial talus landforms, mini-thermochrons were deployed in and around potentially ice-embedded features of the Sierra Nevada. Results from pilot studies at 13 rock glaciers and 7 taluses indicate that outlet springs from these landforms generally do not desiccate but persist year-round as ice (frozen) in winter and flowing water in the warm season. Temperatures of water (liquid and ice) in rock-glacier outlet springs had an annual mean of −0.2 °C and mean of 0.6 °C during the warm season with very low diurnal fluctuation. These and other attributes suggest the existence of internal ice and/or permafrost supplying the springs. Air temperatures of rock-glacier matrices (1 m below the surface) versus surface air corroborate the periglacial nature of internal environments: annual air temperatures of matrices were below freezing (mean, −0.8 °C). Compared to surface air, especially during the warm season, matrix air temperatures were significantly colder and fluctuated less. Talus landforms followed a similar pattern, although water- and matrix air temperatures were warmer, and contrasts with surface air were not as strong as for rock glaciers. For rock glaciers and talus slopes, matrix air temperatures showed resistance (buffering) to changes in external air temperatures. Unique geomorphic conditions of rock glaciers and periglacial taluses in the Sierra Nevada appear to maintain cool-buffered thermal regimes at least partly decoupled from external air. Springs support persistent wetlands and lakes at their snouts, retaining water in otherwise semi-arid high cirques, and contribute as hydrologic reserves and critical habitat for alpine biota. Daily and seasonal lags and buffering effects suggest that ice within these landforms might resist surface warming on the longer term, which could make these landforms increasingly important as regional climates change. [ABSTRACT FROM AUTHOR]

Abstract: During the 2011–2012 austral summer, we had the opportunity to verify a surficial geology map prepared nearly 50years ago for the Victoria Valley system (VVS), the largest of the McMurdo Dry Valleys. We used high-resolution landsat images and a digital elevation model to identify landforms and prepare detailed maps of each of the five valleys in the VVS, including lateral and end moraines, rock glaciers, gelifluction sheets, gravel ripples, and hummocky and ice-cored drifts. Our mapping suggests that the Bull drift is less extensive than previously thought, attains a maximum elevation of ~750m in Balham and Barwick Valleys and the upper Bull Pass region, and does not occur in McKelvey Valley. We found Insel drift to 850m elevation in eastern McKelvey Valley and upper Bull Pass and were able to trace Insel drift down Bull Pass where it becomes Peleus drift in Wright Valley. The Victoria Lower Glacier likely responded to grounding of ice in the Ross Embayment and was out-of-phase with alpine glaciers elsewhere in the VVS. We amplified and quantified Calkin's relative chronology and provide here our multiple-parameter relative chronology for the McMurdo Dry Valleys that is based on surface-boulder weathering, soil weathering, salt stage, degree of development of the desert pavement, and form of patterned ground. Except for Victoria Lower Valley, we correlate Packard drift with Taylor II drift (ca., 120ka), Vida drift with Taylor III drift (ca., 300ka), Bull drift with Taylor IVb drift (2.7–3.5Ma, and Insel drift with Peleus drift (>3.7Ma, <5.4Ma). The lack of a strong correlation between soil salt stage and depth of visible salts with elevation leads us to question whether a high-level lake (ca., 200m deep) existed in the VVS during the early Holocene. [Copyright &y& Elsevier]

Abstract: We present a regional inventory of rock glaciers (n =1514) and protalus ramparts (228) for the Lombardy region, central Italian Alps. To identify and classify the landforms we inspect three sequential air-orthophoto mosaics and a 2m-DSM, and conduct confirmatory field work. The inventory forms an empirical basis to analyze: (i) the relative contribution of hillslope (i.e., talus slopes) and glacial (i.e., moraines) sediment stores to rock glacier sediment supply; (ii) linkages between the landforms inventoried and local topographic attributes; (iii) the spatial variability of periglacial activity in relation to a parsimonious set of environmental variables (i.e., elevation, precipitation, and lithology); and (iv) the effects of the Pleistocene–Holocene climatic transition on the distribution of intact and relict landforms. This analysis reveals that the elevation of rock glacier termini can vary over 200m as a function of slope aspect. In turn, the distribution of rock glaciers among aspect categories is controlled by the structure of the valley network that promotes NW and SE exposures. Talus rock glaciers prevail numerically over the glacier-related typology, even though the latter population appears to have increased during the Holocene. Relict and intact rock glaciers have distinct spatial patterns in that the former display, on average, a 400-m elevation drop and a less clustered distribution towards northern aspects, suggesting that they have developed in more “permafrost-prone” climatic conditions. Analyzing the study region through a 27.5km-grid has been instrumental for showing that the rock glacier specific area and terminus elevation are: (i) positively correlated with terrain elevation; and (ii) negatively correlated with mean annual precipitation. As a consequence, in relation to Holocene generalized atmospheric temperature rise, intact rock glaciers have progressively disappeared from the wetter and milder portions of the central Italian Alps. Analysis of rock glacier occurrence across litho-tectonic sectors does not provide conclusive dependences and requires further analysis. This inventory, which represents a necessary preliminary step for modelling the spatial distribution of discontinuous permafrost at the regional scale, fills a critical geographic gap in the context of ongoing permafrost research in the European Alps (e.g., PermaNET). [Copyright &y& Elsevier]

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Lilleøren, K.S. and Etzelmüller, B., 2011.Aregional inventory of rock glaciers and ice-cored moraines in Norway. Geografiska Annaler: Series A, Physical Geography, 93, 175-191. DOI: 10.1111/j.1468-0459.2011.00430.x ABSTRACT Landforms in Norway indicating present and former permafrost have been compiled in order to discuss Holocene landform development patterns. In total 307 permafrost landforms have been mapped, consisting of rock glaciers and ice-cored moraines. The landforms were classified as active/inactive (intact) or relict landforms, and by origin. In northern Norway, permafrost landforms exist down to sea level and the majority of the landforms are relict talus-derived rock glaciers. In southern Norway, permafrost landforms are restricted to high elevations and the majority of the landforms are connected to glacial activity and classified as active. In the present paper, this contrasting pattern is interpreted to reflect that different processes leading to a permafrost landform also represent different ages and climatic regimes during their formation. The inventoried landforms reproduce the modelled permafrost distribution for Norway satisfactorily. [ABSTRACT FROM AUTHOR]

Abstract: Whether rock glaciers are permafrost creep features or may also be related to glaciers in non-permafrost environments, and whether they should be defined by genesis or appearance, have caused heated debate for several decades. This paper analyses the rock glacier debate from a theoretical viewpoint, in order to highlight and discuss underlying problems and with the aim of providing a common conceptual framework from which to proceed. It is suggested that the morphological rock glacier definition should be abandoned. A new genetic definition is proposed where permafrost is the primary condition, but where the deforming ice/debris may be of both glacial and periglacial origin. [Copyright &y& Elsevier]

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A ten-year (1993-2003) geodetic survey was conducted at the Besiberris rock glacier, a tongue-shaped, glacigenic rock glacier, located in the eastern-central Spanish Pyrenees (42º35′48″N, 0º49′20″E). Displacement measurements were made on three traverse lines across the rock glacier and mapped by geostatistical kriging interpolation methods. Surface horizontal velocity increases from the head to the toe sectors (average values: traverse line A = 8.72 cm yr-1; line B = 10.65 cm yr-1; line C = 13.35 cm yr-1). Velocities are greater at the axis of the rock glacier compared to its lateral margins. In terms of vertical movement, the rock glacier has shown clear thinning of an ice-core. In all three traverse lines, surface lowering has been detected (average values: line A = 5.00 cm yr-1; line B = 7.10 cm yr-1; line C = 5.27 cm yr-1). This general lowering is interpreted as the adjustement of the rock glacier to the climatic amelioration (higher temperature, drier conditions and reduced snowfall) observed in the Pyrenean region since the end of the Little Ice Age and accentuated in the last few decades. [ABSTRACT FROM AUTHOR]

Copyright of Cuadernos de Investigación Geográfica is the property of Universidad de la Rioja, Servicio de Publicaciones and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: The impact of the Late Palaeozoic glaciation of Gondwana is documented in northern Ethiopia both by glaciogenic sediments and by palaeolandforms of glacial erosion, yet the palaeoglaciological conditions that existed in this region during the glaciation haven''t been investigated so far. In northern Ethiopia, erosional landforms of the Late Palaeozoic glaciation are exposed over an area of at least several tens of km2. These palaeolandforms are described for the first time and their origin and significance as indicators of regional ice-flow direction, glacial palaeolandscape and ice dynamics are discussed. The palaeolandforms of glacial erosional occur mainly on Precambrian basement rocks being directly overlain by glaciogenic sediments of latest Carboniferous to Early Permian age. Landforms are highly diverse and include, among others, chatter marks, muschelbrüche, whalebacks and rock drumlins. All these palaeolandforms indicate that the region was occupied by predominantly wet-based, temperate and relatively mobile continental glaciers during the Late Palaeozoic. The erosional surface that occurs at the base of the glaciogenic sediments represents a palaeolandscape of areal scour formed mainly by glacial abrasion and to a lesser extent by quarrying beneath a continental ice sheet, whereas meltwater erosion played only a minor role in its genesis. A northward-directed palaeo-ice flow is indicated by the orientation of palaeolandforms such as wedge striae, crescentic gouges, lunate fractures and roche moutonnées. This suggests, that the glaciers were sourced by ice sheets located in central Africa or in the Horn of Africa. Glacial advances might have extended into Arabia, albeit this scenario is not yet proven. [Copyright &y& Elsevier]