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Rock‐ice avalanches have frequently occurred in the Eastern Himalayan Syntaxis region due to climate change and active tectonic movements. These events commonly trigger catastrophic geohazard chains, including debris flows, river blockages, and floods. This study focuses on the Zelongnong Basin, analyzing the geomorphic and dynamic characteristics of high‐altitude disasters. The basin exhibits typical vertical zonation, with disaster sources initiating at elevations exceeding 4000 m and runout distances reaching up to 10 km. The disaster chain movement involves complex dynamic effects, including impact disintegration, soil‐rock mixture arching, dynamic erosion, and debris deposition, enhancing understanding of the flow behavior and dynamic characteristics of rock‐ice avalanches. The presence of ice significantly increases mobility due to lubrication and frictional melting. In the disaster event of September 10, 2020, the maximum flow velocity and thickness reached 40 m/s and 43 m, respectively. Furthermore, continuous deformation of the Zelongnong glacier moraine was observed, with maximum cumulative deformations of 44.68 m in the distance direction and 25.96 m in the azimuth direction from March 25, 2022, to August 25, 2022. In the future, the risk of rock‐ice avalanches in the Eastern Himalayan Syntaxis region will remain extremely high, necessitating a focus on early warning and risk mitigation strategies for such basin disasters. [ABSTRACT FROM AUTHOR]

Global warming has accelerated alpine glacier melting and led to an increased risk of glacial lake outburst floods (GLOFs). This paper extracted glacial lake boundaries in the Tienshan Mountains of Central Asia from 1990 to 2023, analyzed their spatiotemporal variations and evaluated their risk levels under current and future scenarios. The results show that glacial lakes are predominantly distributed in the Central and Western Tienshan, accounting for 75% of the total number in the Tienshan region. The number and area of glacial lakes increased by 148% (from 1837 to 4557) and 71.83% (from 119.73 to 205.73 km2) during 1990 to 2023, with moraine lake expansion predominating. In the Western Tienshan, the high or very high risk of GLOF is 3–4 times that of other areas. By the middle of the twenty-first century, GLOF risk will continue to increase, especially in the Western Tienshan. This study can provide scientific foundation for disaster mitigation in the downstream areas. [ABSTRACT FROM AUTHOR]

This study identifies the reasons for geodynamics variability of the coastal system within two cliff-shore sections of the southern Baltic Sea (SBS). The comparative analysis included distinct moraines and their foregrounds near the open sea (S1) and within the Gulf of Gdańsk (S2). Short-term trends indicate a direct link between landslide occurrence and increased cliff retreat. Long-term (total) values were obtained by developing the 4F MODEL for large-scale applications, based on the analysis of remote sensing and hydroacoustic data (to determine the extent of shore platforms), the modelling of higher-order polynomial functions describing their extent, followed by the integral calculus of the indicated functions within the open-source Desmos environment. The retreat dynamics for individual landslides (S1) was an order of magnitude higher (m/yr) than the average for the whole cliff section (0.17 ± 0.008 m/yr), which correlates well with medium- and long-term development tendencies and recession dynamics, revealed by the numerical modelling method, since approximately 8 ka b2k, years before 2000 CE (at S1 = 0.17 ± 0.020 m/yr, at S2 = 0.11 ± 0.005 m/yr). While the approach described in this paper can reveal, project, and simulate the dynamics of past and future trends within other cliffed coasts shaped in tideless conditions, it also proves stable moraine erosional responses to sea-level rise since the Mid-Holocene. [ABSTRACT FROM AUTHOR]

The Skaftafellsjökull is an outlet glacier in southern Iceland that has been retreating since 1890. While multiple studies have examined primary succession on the foreland of this glacier, no study has examined the distribution of woody biomass on the outwash plain. We investigated the distribution of one species, Betula pubescens, that grows on the foreland moraines and outwash plain of this glacier. The topography of the outwash plain is heterogeneous, consisting of broad bars of outwash gravel and boulders that are separated by narrow incised channels and broader swales. Vegetation on the outwash plain is primarily a moss–heath community. Birch are sparse on the outwash bar tops, but are more abundant and larger in the channels and swales between the bars. Although the area of the channels on the outwash plain is much less than that of the bar surfaces, the woody biomass of the outwash plain is dominated by the birch within these channels. Consequently, the mean woody biomass of the outwash plain exceeds that of the moraines. We propose that the microhabitat of the outwash plain channels provides a favorable environment for the growth of birch, primarily by providing a fine-grained substrate that promotes successful seeding and growth. [ABSTRACT FROM AUTHOR]

The Skaftafellsjökull is an outlet glacier in southern Iceland that has been retreating since 1890. While multiple studies have examined primary succession on the foreland of this glacier, no study has examined the distribution of woody biomass on the outwash plain. We investigated the distribution of one species, Betula pubescens, that grows on the foreland moraines and outwash plain of this glacier. The topography of the outwash plain is heterogeneous, consisting of broad bars of outwash gravel and boulders that are separated by narrow incised channels and broader swales. Vegetation on the outwash plain is primarily a moss–heath community. Birch are sparse on the outwash bar tops, but are more abundant and larger in the channels and swales between the bars. Although the area of the channels on the outwash plain is much less than that of the bar surfaces, the woody biomass of the outwash plain is dominated by the birch within these channels. Consequently, the mean woody biomass of the outwash plain exceeds that of the moraines. We propose that the microhabitat of the outwash plain channels provides a favorable environment for the growth of birch, primarily by providing a fine-grained substrate that promotes successful seeding and growth.

Lago Argentino is one of the largest lakes in Patagonia. Some of its arms host calving glaciers that flow from the southern Patagonian Ice Field. The best known of these is the Perito Moreno glacier. Although recent studies have reconstructed part of glacier dynamics in the southern arms of Lago Argentino, there are no studies yet for the northern arms. A high-resolution seismic survey was carried out in the northern area of Punta Bandera, i.e., in the sector between the Brazo Norte and the Canal de los Témpanos to characterize the stratigraphy of the sedimentary fill of the lake and identify the main unconformities related to glacial dynamics. Eight seismic facies grouped into two seismic units were mapped, and ten unconformities were recognized. Based on the acquired data, a bathymetric grid was created for the first time to obtain a morphological representation of the lake floor and access to a previously unmapped area of Lago Argentino. The analysis of the geometries and acoustic properties of the different seismic facies identified, correlated with the available information on land moraines, has allowed us to partially reconstruct the advance and retreat phases of the glacial lobes that formerly were present in the two arms of the lake, although the temporal assignments are still speculative due to the lack of calibrations with boreholes. Nevertheless, this study provides important information for deciphering the glaciation history of a key sector of the southern Patagonian Ice Field during the late Pleistocene/Holocene. The data show that the northern and southern areas have different lake floor morphologies, with the southern, shallower area of the Canal de los Témpanos being glaciated first than the northern, more overdeepened area of the Brazo Norte. [ABSTRACT FROM AUTHOR]

Outburst floods from glacial Lake Missoula largely explain erosion of the Channeled Scabland, a system of overfit, basaltic channels in Washington, northwestern United States. However, it is challenging to explain Missoula flood routing into Moses Coulee due to its topographic isolation from flood routes. To clarify flood pathways into Moses Coulee, we mapped channels that delineate a radial-anastomosing network connecting to Moses Coulee. Channels consist of coulee-like features eroded mainly in basalt. Channels climb adverse slopes and cross divides, and the network is draped with eskers and recessional moraines. These channel geometries and glacial landform associations suggest a tunnel channel network. Large channel dimensions and network anastomosis indicate formation in subglacial floods. The network connects to Moses Coulee with sufficient cross-sectional area to convey megafloods, hinting that subglacial floods may have been a significant source of Moses Coulee meltwater, in addition to possible diverted Missoula floods. [ABSTRACT FROM AUTHOR]

One of the more visible consequences of anthropogenic climate change is the ongoing retreat of glaciers worldwide. Rates of primary succession in the resulting glacial forelands are commonly calculated from a single measurement set using a single set of measurements across a landscape of varying age, but repeated measurements over decadal scales may be a more effective means of examining the rates and trends of colonization and community development. Repeated measurements of vegetation groups in a glacial foreland in southern Iceland demonstrate that successional changes are measurable, as shown by the calculation of the dissimilarity index at sites over a 15 year interval. Inter-site dissimilarity validates the essential paradigm of primary succession, where vegetative coverage increases in the glacial foreland as a function of time and supports earlier interpretations saying that species richness decreases on older surfaces, even as the total vegetation cover increases. However, successional processes are subject to major abiotic factors, such as aspect, which is controlled by landscape topography, and the substrate composition. The glacial moraines and outwash plain are underlain by different substrates which produce separate successional trajectories. Succession on the moraines ultimately produces a birch-shrub-heath community, while the outwash deposits promote development of a moss-heath community. [ABSTRACT FROM AUTHOR]

Moraines, characterized by the accumulation of rock and soil debris transported by glacial activity, present unique challenges for tunnel construction, particularly in portal sections, due to prevailing geographical and climatic conditions that facilitate freeze-thaw action. Despite these challenges, there is a dearth of studies investigating the influence of freeze-thaw action and water content on the mechanical properties of moraines, and no research on calculating surrounding rock pressure in moraine tunnels subjected to freeze-thaw conditions. In this study, direct shear tests under freeze-thaw cycles were conducted to examine the effects of freeze-thaw cycles and water content on the mechanical properties of frozen moraine. A comprehensive parameter K, integrating the number of freeze-thaws and water content, was introduced to model cohesion c. Drawing on Terzaghi Theory, we propose an improved algorithm for calculating surrounding rock pressure at the portal section of moraine tunnels. Using a tunnel as a case study, surrounding rock pressure was calculated under various conditions to validate the Improved Algorithm's efficacy. The results show that: (1) Strength loss exhibits a linear trend with the number of freeze-thaw cycles at water content levels of 4% and 8%, while at 12% water content, previous freeze-thaw cycles induce more significant damage to the soil. (2) Moraine saturation peaks between 8% and 12% water content. Following repeated freeze-thaw cycles, moraine shear strength initially increases before decreasing with varying water content. (3) The internal friction angle of moraine experiences slight reductions with prolonged freeze-thaw cycles, but both freeze-thaw cycles and water content significantly influence cohesion. (4) Vertical surrounding rock pressure increases after the initial freeze-thaw cycle, particularly with higher water content, although freeze-thaw cycles have minimal effect on it. (5) Freeze-thaw cycles lead to a substantial increase in lateral surrounding rock pressure, necessitating reinforced support structures at the arch wall, arch waist, and arch foot in engineering projects to mitigate freeze-thaw effects. This study provides a foundation for designing and selecting tunnel support structures in similar geological conditions. [ABSTRACT FROM AUTHOR]

Beryllium-10 cosmic-ray exposure (CRE) dating has revolutionized our understanding of glacier fluctuations around the globe. A key prerequisite for the successful application of this dating method is the determination of regional production rates of in situ accumulated 10 Be, usually inferred at independently dated calibration sites. Until now, no calibration site has been available for the mid-elevation mountain ranges of central Europe. We fill this gap by determining in situ 10 Be concentrations in large boulders on moraines and by applying radiocarbon and infrared-stimulated luminescence (IRSL) dating to stratigraphically younger lake sediments in the southern Black Forest, SW Germany. The dating methods yielded concordant results, and, based on age–depth modelling with 14 C ages, the age of a cryptotephra, and IRSL ages, we deduced a regional 10 Be production rate in quartz. Calibrating the Black Forest production rate (BFPR) in the Cosmic-Ray Exposure program (CREp) resulted in a spallogenic sea-level and high-latitude (SLHL) production rate of 3.64±0.11 atoms 10 Be g -1 quartz a -1 when referring to time-dependent Lal–Stone scaling, the European Reanalysis (ERA)-40 atmosphere model, and the atmospheric 10 Be-based geomagnetic database in CREp. The BFPR turned out to be ∼11 % lower than both those at the nearest calibration site in the Alps (4.10±0.10 atoms 10 Be g -1 quartz a -1 at SLHL) and the canonical global 10 Be production rate (4.11±0.19 atoms 10 Be g -1 quartz a -1 at SLHL) in CREp. A stronger weathering and snow cover bias and a higher impact of forest, soil, moss, and shrub cover at the study site likely explain this discrepancy. [ABSTRACT FROM AUTHOR]

We report new cosmogenic 21Ne-in-quartz exposure ages from 18 samples on three distinct moraines deposited in the Lost Creek drainage, approximately 3–7 km down-valley from Lassen Peak in Lassen Volcanic National Park. Although measuring 21Ne in quartz is generally straightforward, accurate 21Ne exposure dating of deposits of late Pleistocene-age is rarely possible due to the significant quantities of non-cosmogenic 21Ne present in most lithologies. Young quartz-bearing volcanic rocks have been observed to be an exception. We take advantage of moraine boulders sourced from the ~28 ka dacite of Lassen Peak to generate a chronology of alpine deglaciation in Lassen Volcanic National Park. Ages from three distinct moraines are in stratigraphic order, ranging ~22–15 ka, and generally agree with other terminal and some recessional moraine ages across the Cascades and Sierra Nevada Range of the western United States. To date, these are among the youngest surfaces ever dated using cosmogenic 21Ne and provide a cost-effective proof-of-concept approach to dating moraines where applicable. [ABSTRACT FROM AUTHOR]

Shergottite meteorites, classified as depleted, intermediate, or enriched based on incompatible trace elements and specific radiogenic isotope compositions (Sr, Nd, and Hf isotope ratios), point to multiple Martian mantle source regions. The oxygen fugacity (f O 2) of these mantle regions, determined from early crystallizing minerals using the olivine-pyroxene-spinel oxybarometer, appears to correlate with incompatible trace element enrichment and isotope compositions. However, values derived from the vanadium-in-olivine oxybarometer challenge this correlation, hinting at potential biases in oxybarometry or complexities in the redox conditions of the Martian mantle. By analyzing the intermediate shergottite Northwest Africa (NWA) 11043 with various oxybarometers, this study deduced its origin from a reduced mantle source, with an average f O 2 value of −0.77 ± 0.35 relative to the iron-wüstite (IW) buffer. Notably, these values coincide with those of depleted shergottites, which represent the depleted Martian mantle region. This redox similarity between intermediate and depleted shergottites contrasts with earlier notions that postulated intermediate shergottites as a mix of depleted and enriched mantle derivatives. Moreover, intermediate shergottites such as NWA 11043, Elephant Moraine (EETA) 79001A, and Allan Hills (ALH) 77005 display 176Hf/177Hf values akin to those of depleted shergottites, suggesting that intermediate mantle components can be separated from the depleted mantle source at approximately 2.2 Ga based on model age calculations. Therefore, there presents a consistent redox state between mantle magma sources of both intermediate and depleted shergottites since the Hesperian period, while enriched shergottites lean toward more oxidized conditions past source formation. This study prompts a reassessment of conventional theories, emphasizing the nuanced redox evolution of the Martian mantle across distinct mantle source regions and underscoring the complexity of the redox evolution of the Martian mantle. The emergence of chemically diverse mantle reservoirs might predominantly arise from early magma ocean differentiation processes, albeit with inherent oxidation nuances. The differences in f O 2 observed between intermediate and depleted shergottites underscore the need for more in-depth studies to decipher Martian mantle differentiation and evolution. [ABSTRACT FROM AUTHOR]

Piedmont glaciers (lobes), typically found in high latitudes and large mountainous regions, extend from ice sheets and ice caps to lower altitudes. However, they can also occur, although less commonly, on mid‐latitude mountains. When these fan‐like glaciers retreat, they leave behind hummocky moraines scattered in a chaotic pattern. In this study, we have mapped one of these mid‐latitude sites and established a Terrestrial cosmogenic nuclide (TCN) glacial chronology on Mount Davraz, namely Davraz hummocky moraine field (37°46′00″N, 30°43′15″E). Our findings indicate that the glaciers in this area started receding from the early local Last Glacial Maximum (LGM) period (21.8 ± 2.4 ka) to the early Late‐glacial period (17.7 ± 2.2 ka), and eventually disappearing. The deglaciation of the Mt. Davraz palaeoglacier matches nearby mountains, supported by southerly winds as significant for regional glaciation. Our discoveries reveal a robust connection between southerly winds and nearby glaciation, contributing to our understanding of how climate influences glaciers. Likewise, the glacial timelines of the neighbouring mountains align with the glacial history of Mt. Davraz. [ABSTRACT FROM AUTHOR]

In order to solve the problem of ground collapse and mudslide caused by the accumulation of loose moraine on the surface of Pulang copper mine in the process of mining, this article prepared a solidified material to solidify moraine with water glass composite ester curing agent. The compressive strength of moraine solidified body was studied, and the consolidation mechanism of water glass composite ester curing agent for consolidating moraine was explored through XRD, FTIR, DSC-TG and SEM. The results show that the moraine solidified body 28 d compressive strength can reach up to 2.05 MPa, indicating good consolidation performance. Under the action of ester curing agent, the hydrolysate of water glass reacts with the hydrolysate of ester curing agent to produce sodium acetate and silicon gel, and silicon gel plays a role in filling the gap between moraine particles and cementing moraine particles. [ABSTRACT FROM AUTHOR]

The retreat of mountain glaciers inevitably leads to an increase in the number of outburst moraine lakes. One of the possible mechanisms of moraine dam outburst along with overflow over the crest is the formation of a filtration channel in the body of the moraine dam (piping). An algorithm for calculating the outburst flood hydrograph, describing the development of a filtration channel in the body of a moraine dam and the subsequent formation of water overflow when the soil above the channel collapses, is proposed in this paper. Verification of proposed methodology was carried out on the basis of experimental data and published data of real outbursts. Satisfactory results verifying this methodology made it possible to use the proposed methodology for the calculation of the hydrograph of the outburst of Lake Bashkara in the Elbrus region, which occurred on 1 September 2017. It is shown that the simulation results are quantitatively comparable with the estimates obtained from field data: the time of water discharge through the channel was 16 min, the period of the outburst wave passage was 40 min, and the maximum discharge was 636 m3/s. Thus, the possibility of applying the proposed methodology for calculating the destruction of natural moraine dams has been demonstrated. [ABSTRACT FROM AUTHOR]

Machine learning is a powerful yet underutilised tool in geomorphology, commonly used for image-based pattern recognition. Analysing new high-resolution (1–10 m) elevation datasets, we investigate its usefulness for detecting discrete geomorphological features. This study develops a machine-learning-based method for identifying ribbed moraines in digital elevation data and progresses to test its performance versus time-consuming, manual methods. Ribbed moraines share geomorphometric characteristics with other glacial landforms, hence representing a valuable test of our new methodology in terms of differentiating between similar features, and for detecting landforms with similar characteristics. Furthermore, mapping ribbed moraines may provide valuable indications of their origin, a topic of debate within glacial geomorphology. To automatically detect ribbed moraines, we extract simple morphometrics from high-resolution digital elevation model data and mask regions where ribbed moraines are unlikely to form. We then test several machine learning algorithms before examining the best performer (K -means clustering) for three study areas of 15 km 2 in Norway. Our results demonstrate a balanced accuracy of 65 %–75 % when validating versus ground-truthing. The performance depends on the availability of high-resolution elevation data in Norway that are needed to resolve the spatial scale of the target (10–100 m). We find the method effective at detecting both fields of ribbed moraines, as well as individual ribbed moraines. We propose pathways for the future implementation of this method on a large scale and for increasing the detail of information gained about detected landforms. In conclusion, we demonstrate K -means clustering as a promising method for detecting ribbed moraines, with great potential to reduce the time needed to produce landform maps. [ABSTRACT FROM AUTHOR]

Glaciers reflect integrated climate signals from inter-annual to centennial timescales. In using glacier extent as a climate-change detector, the challenge is to distinguish the roles of the inter-annual climate variability and long-term climatic change on the glacier change. Using cosmogenic nuclide 10Be dating method and glacier dynamical models, this study numerically reconstructed glacier extents at ~ 1850s AD (latest Little Ice Age period) in the Keqiong Qu I, Keqiong Qu II, Taqiong Qu I, and Taqiong Qu II valleys around the Kuoqionggangri peak, southern Tibetan Plateau, and quantified the effects of inter-annual summer temperature variability and long-term summer temperature change on the glacier retreats since then. Without change in mean annual precipitation, the summer temperature decrease of 0.40–0.53 °C from present was required to sustain the glacier lengths at their respective ~ 1850s AD moraines in the four valleys. The climate inferences from the glacier-climate modeling were similar to reconstructions at other glaciers on the Tibetan Plateau and the changes in long term climate reanalysis (HadCRUT5, BEST and NOAA 20CR v3). Forced by the inter-annual variabilities in summer temperature and annual precipitation, the glaciers had excursions of 150–200 m (5–8% of their lengths) from the ~ 1850s AD moraines. We therefore argued that the climate change was largely responsible for the glacier retreats from the ~ 1850s AD moraine positions in the region. [ABSTRACT FROM AUTHOR]

ABSTRACTWe present a 1:15,000 geomorphological map of the Maladeta massif in the Central Pyrenees. Our methodology includes fieldwork, the analysis of aerial photographs from 1956 to 2015, and the use of drone flights from 2020 to 2023. The study area consists mainly of granodiorite but also has outcrops of limestone, shales, and quartzites at lower elevations. The landscape of the Maladeta massif is primarily shaped by glacial and periglacial processes, with fluvial, karstic, and hillslope dynamics manifesting in the lower regions. The assessment of moraine thickness has facilitated the determination of maximum glacier thickness during the Little Ice Age (LIA) and has shown that there is no correlation between ice thickness and glacier extent. After the LIA, the massif experienced a continuous glacier retreat. Currently, only 21.4% of the glacier area observed in 1956 remains.

ABSTRACTGlacial geomorphological mapping from the southern margin of Skálafellsjökull, southeast Iceland, depicts a topographically diverse mountainside, influencing glacier dynamics, landform formation and glacier retreat since the Little Ice Age maximum in ∼1890. The glacial landforms present are typical of southeast Icelandic temperate glaciers, comprising recessional push moraines, including sawtooth moraines, and associated fluting. Study area A demonstrates an abandoned lobe confined by steep V-shaped topography, displaying moraines and minimal fluting, suggesting low preservation of landforms, and changes in glacier behaviour. At study area B, the sawtooth moraine morphology demonstrates changes in the glacier margin as the ice interacted with a series of topographic benches during active recession. The steep-sided valley at study area C illustrates densely spaced arcuate moraines, reflecting subtle changes in ice elevation. This mapping provides a framework for further investigations into glacier retreat rates and the influence of local topography and climate.

Surface exposure–age dating was applied to rock surfaces associated with ice‐marginal moraines at elevations of ~1520–1780 m a.s.l. on the slopes of Galdhøpiggen and Glittertinden, the two highest mountains in Scandinavia located in the Jotunheimen mountains of central southern Norway. This is important for understanding the pattern and timing of wastage of the Scandinavian Ice Sheet at the Younger Dryas–Holocene transition. Cosmogenic exposure dating (here 10Be dating) of boulders from the moraine ridges yielded overall mean ages (corrected for glacio‐isostatic uplift, surface erosion and snow shielding) of ~11.6 ka from Galdhøpiggen and ~11.2 ka from Glittertinden. Similar 10Be ages were also obtained from additionally collected proximal and distal erratic boulders and bedrock samples. These enabled age calibration of Schmidt‐hammer R‐values and independent Schmidt‐hammer exposure‐age dating (SHD) of the moraine ridges, which yielded comparable mean SHD ages of ~10.8 and ~10.6 ka from the Galdhøpiggen and Glittertinden sites, respectively. Taking account of the age resolution and other limitations of both dating techniques, the results suggest that the two sets of moraines have approximately the same age but that neither technique can distinguish unambiguously between moraine formation in the late Younger Dryas or Early Holocene. Together with features of moraine‐ridge morphology and estimates of equilibrium‐line altitude depression of ~360–575 m (corrected for land uplift), the results imply moraine formation during short‐lived re‐advances of active glaciers, at least the lower reaches of which were warm‐based. It is concluded that the local glaciers remained active and advanced during deglaciation either very late in the Younger Dryas or very early in the Holocene, possibly in response to the Preboreal Oscillation at ~11.4 ka. The study supports the concept of a thin Younger Dryas ice sheet and places time constraints on the timing of final deglaciation in southern Norway. [ABSTRACT FROM AUTHOR]

Moraine dam breaches occur suddenly and have severe consequences. However, breach-process prediction is challenging. Breach-notch excavation is crucial for risk reduction, but no consensus have been reached regarding the optimal notch shape. This study considers the typical characteristic parameters of the Jialongcuo glacial lake and trapezoidal, triangular, and compound notches. In this study, three flume tests were conducted to study the breach-shape impact on the peak discharge and erosion development of the dam during dam-breaching process, while controlling the excavation volume and depth. The compound- and triangular-breach peak discharge values surpass that of the trapezoidal type by 18.4% and 12.2%, respectively. Additionally, the trapezoidal breach exhibits average erosion rates that are > 50% lower, both laterally and vertically, at its initial erosion section, indicating milder erosion and improved outflow efficiency. The results emphasize that the notch-bottom width is critical, and that a trapezoidal notch with equal depths yields higher initial outflow efficiency owing to its greater bottom width. An analysis based on dam erosion process theory agrees with the experimental results and confirms the conclusions. Based on the erosion rates taken from the experiments, a comparison of sediment transport values is given for the three tests. The results indicate that the trapezoidal notch has a relatively small bed load transport. Our work is expected to provide references for the selection of better notch shape. [ABSTRACT FROM AUTHOR]

Diamer Basha Dam is an under-construction, 272-meter-high, roller compacted concrete (RCC) dam on the Indus River in Pakistan. Once constructed, it will be the world's highest RCC gravity dam with a 105-kilometer-long reservoir. Most of the reservoir lies in unstable moraine deposits with steep slopes. Events like saturation during reservoir filling, alternate wetting, drawdown during reservoir operation, or a seismic event could trigger a large mass movement of these slopes into the reservoir to disrupt the dam functionality. This work identified the 15 most vulnerable slide areas using digital slope maps, elevation maps, and satellite imagery. Deterministic slope stability analysis was carried out on the identified sections under various stages of reservoir operation for static and seismic loading, using pseudo-static and dynamic analysis approaches. Probabilistic analysis was then performed using Monte Carlo simulation. The findings showed that most moraine deposits would collapse under reservoir filling, rapid drawdown, or seismic activity. Following the assessments, landslide susceptibility maps were generated, and an assessment of potential impacts, including the generation of dynamic waves, reservoir blockage, increased sediment loads, and reduced reservoir storage capacity, was also performed. [ABSTRACT FROM AUTHOR]

Landslides are one of the most damaging natural hazards and have killed tens of thousands of people around the world over the past decade. Slow‐moving landslides, with surface velocities on the order of 10−2–102 m a−1, can damage buildings and infrastructure and be precursors to catastrophic collapses. However, due to their slow rates of deformation and at times subtle geomorphic signatures, they are often overlooked in local and large‐scale hazard inventories. Here, we present a remote‐sensing workflow to automatically map slow‐moving landslides using feature tracking of freely and globally available optical satellite imagery. We evaluate this proof‐of‐concept workflow through three case studies from different environments: the extensively instrumented Slumgullion landslide in the United States, an unstable lateral moraine in Chilean Patagonia and a high‐relief landscape in central Nepal. This workflow is able to delineate known landslides and identify previously unknown areas of hillslope deformation, which we consider as candidate slow‐moving landslides. Improved mapping of the spatial distribution, character and surface displacement rates of slow‐moving landslides will improve our understanding of their role in the multi‐hazard chain and their sensitivity to climatic changes and can direct future detailed localised investigations into their dynamics. [ABSTRACT FROM AUTHOR]

Triaxial tests were performed on samples of unsaturated moraine soil at a high-plateau airport of China by using the unsaturated soil triaxial apparatus. In the tests, the matric suction and net confining pressure were controlled. In the scheme of the tests, the matric suctions were controlled at 0 kPa, 50 kPa, 100 kPa and 200 kPa. The net confining pressures were controlled at 100 kPa, 200 kPa, 300 kPa and 400 kPa. The results showed that for the unsaturated moraine soil, c' and φ ' increase in the matric suction and their growth rates were similar. The relationship between volumetric strain and net confining pressure showed that the specimens were in a state of dilatancy with a small net confining pressure and the amount of dilatancy rapidly decreased and developed into a shear shrinkage state with an increase in net confining pressure. The last amount of shrinkage was stable at approximately 0.6%. Also, the soil suction characteristic curve for the studied soil was obtained by the tests and the suction stress increased with the matric suction. [ABSTRACT FROM AUTHOR]

The Sandy Lake basin in northwestern Ontario is a potentially important area for insights into the late history of glacial Lake Agassiz because of its extensive glaciolacustrine deposits and well-preserved shoreline features of this geological episode. However, little information is available on its deglaciation history. Recent mapping shows the withdrawal of the ice from the basin center and subsequent deposition of extensive varved clay in the lake with an optically stimulated luminescence-dated maximum age at 11.4 ± 0.9 ka. With its further recession, the ice constructed the Opasquia moraine on the northern rim of the basin sometime before the development on the moraine of the first major shoreline of the lake (the The Pas, inferred at 10.1 ka). Lowering of the lake level formed many strandlines on the moraine and elsewhere in the basin, which can be correlated with those in the main Agassiz basin based on projected water planes (the The Pas to Ponton). Radiocarbon dating on basal wood remains of surface peat in a former strait defined by the Ponton shoreline and a nearby site on the former lake floor indicates the abandonment of this shoreline and hence the withdrawal of Lake Agassiz from the Sandy Lake basin by 8.3 ± 0.1 cal ka (UOC-7883). The date, although a minimum-limiting age, provides the hitherto best possible age constraint for the Ponton–Kinojévis shorelines, which many hypothesize represent one of the major lake levels during the final drainage of Lake Agassiz into Hudson Bay but have never been adequately dated before. [ABSTRACT FROM AUTHOR]

In order to effectively reduce the risk of underground debris flow, surface moraine is solidified and modified by using grouting technology to realize the change in fine-grained moraine from "powder" to "block" to change the source conditions of underground debris flow and to reduce the risk of moraine from the root. In this paper, the effects of grouting pressure, porosity, and pore diameter on the spillability of moraine are investigated experimentally. The results show that the grouting depth increases linearly with increasing sample porosity. For the same sample density, the grouting pressure is proportional to the grouting depth. As the pore diameter of the sample increases, the longitudinal grouting depth of the sample increases, but the transverse diffusion distance decreases. The chemical grout in the moraine is mainly split-infiltration grouting mode. The present research results can provide effective support for the prevention and control of underground debris flow in Pulang Copper Mine. [ABSTRACT FROM AUTHOR]

Reconstructing interglacial marine environments helps us understand the climate change mechanisms of the past. To contribute to this body of knowledge, we studied a high-resolution 455 cm-thick sediment sequence of the Boreal (Eemian) marine beds directly overlying Moscovian (Saalian) moraine in the Bychye-2 section on the Pyoza River. We analyzed lithological and microfossil (foraminifers, ostracods, pollen, aquatic palynomorphs) variations at the studied site. Stratigraphical zonation is based on the local and well-established regional pollen zones, correlated with the western European pollen zones. The studied marine beds accumulated from the end of the Moscovian glacial (>131 ka) until ca. 119.5 ka. We distinguished three successive phases: a seasonally sea-ice-covered, relatively deep, freshened basin in the initial rapid flooding stage (>131–130.5 ka); a deep basin in the maximum flooding phase with less extensive sea ice cover (130.5–130.25 ka); and a shallow basin with reduced sea ice cover (130.25–119.5 ka). According to a pollen zone comparison with other sites, the regional glacioisostatic rebound started ca. 130 ka. The diverse warm-water assemblages of benthic foraminifers and ostracods containing typical Baltic Sea species occurred during the regression, mainly 128–124 ka, thus giving evidence for a relatively long-lasting connection between the White and Baltic Seas. [ABSTRACT FROM AUTHOR]

Vermicular Ridge Features (VRFs) comprise a series of ridges and troughs with a circular, sinuous, and anastomosing morphology composed of clast-rich sandy diamict. VRFs were first reported on the south coast of Devon Island, Nunavut, Canada, in the Dundas Harbour region. Here, we document the presence of VRFs near Mokka Fjord on Axel Heiberg Island, Nunavut, Canada. We utilize field observations, ultra high resolution LiDAR, and ground penetrating radar to characterize and compare the morphometry and sedimentology of VRFs near Mokka Fjord to other periglacial, paraglacial, and glacial landforms. VRFs near Mokka Fjord have a diameter ranging from 6 to 37 m and reach up to 1.5 m in height. They comprise clast-rich glaciofluvial sediment and till. A leading periglacial (i.e., segregation ice features/lithalsas) and glacial (i.e., ring-ridge moraines and kame/kettled terraces) origin are presented. We interpret Mokka Fjord VRFs to be an ice-marginal feature resulting from paraglacial ablation of buried glacial ice producing a hummocky ring-ridge moraine comprised of ice marginal and supra- and englacial debris. This formation mechanism would infer a largely polythermal glacial environment with limited water supply. Likely from occasional warm-based periods at the ice margins which may allow sediment output and ice burial from basal ice debris redistribution or the thinning and subsequent burial of snout ice from glaciofluvial outwash. [ABSTRACT FROM AUTHOR]

The timing of the last deglaciation of the Laurentide Ice Sheet in western New York is poorly constrained. The lack of direct chronology in the region has led to a provocative hypothesis that the Laurentide Ice Sheet re-advanced to near its Last Glacial Maximum terminal position in western New York at ~13 ka, which challenges long-standing datasets. To address this hypothesis, we obtained new chronology from the Kent (terminal) and Lake Escarpment (first major recessional) moraines using radiocarbon ages in basal sediments from moraine kettles supplemented with two optically stimulated luminescence ages. The two optically stimulated luminescence ages date the Kent (terminal) position to 19.8 ± 2.6 and 20.6 ± 2.9 ka. Within the sediment cores from both moraines, the lowest reliable radiocarbon ages range from 15,000–15,400 to 13,600–14,000 cal yr BP. Below these dated levels is sedimentologic evidence of an unstable landscape during basin formation; radiocarbon ages from these lowest sediments are not in stratigraphic order and date from 19,350–19,600 to 14,050–14,850 cal yr BP. The oldest radiocarbon age of 19,350–19,600 cal yr BP – from a rip-up clast – suggests ice-free conditions at that time. We interpret that the 5 kyr lag between the optically stimulated luminescence ages and the lowest reliable radiocarbon ages is the result of persistent buried ice in ice-cored moraines until ~15 to 14 ka. The cold conditions associated with Heinrich Stadial 1 may have enabled the survival of ice-cored moraines in permafrost until after 15 ka, and in turn, climate amelioration during the Bølling Period (14.7– 14.1 ka) may have initiated landscape stabilization. This model potentially reconciles the sedimentological and chronological evidence underpinning the provocative re-advance hypothesis, which instead could be the result of moraine instability during the Bølling-Allerød periods (14.7–13 ka). Age control for future work should focus on features that are not dependent on local climate. [ABSTRACT FROM AUTHOR]

We present 40 new 10Be exposure ages of moraines and other glacial deposits left behind by the southeastern sector of the Laurentide Ice Sheet (LIS) in southern New England and New York, summarize the regional moraine record, and interpret the dataset in the context of previously published deglaciation chronologies. The regional moraine record spans the Last Glacial Maximum (LGM), with the outermost ridge of the terminal complex dating to ~26–25 ka, the innermost ridge of the terminal complex dating to ~22 ka, and a series of smaller recessional limits within ~50 km of the terminal complex dating to ~21–20.5 ka. The chronology generally agrees with independent age constraints from radiocarbon and glacial varves. A few inconsistencies among ages from cosmogenic-nuclide measurements and those from other dating methods are explained by geologic scatter where several bedrock samples and boulders from the outer terminal moraine exhibit nuclide inheritance, while exposure ages on large moraines are likely affected by postdepositional disturbance. The exposure-age chronology places the southeastern sector of the LIS at or near its maximum extent from ~26 to 21 ka, which is broadly consistent with the LGM sea-level lowstand, local and regional temperature indicators, and local summer insolation. The net change in LIS extent represented by this chronology occurred more slowly (<5 to 25 m yr-1) than retreat through the rest of New England, consistent with a slow general rise in insolation and modeled summer temperature. We conclude that the major pulse of LIS deglaciation and accelerated recession, recorded by dated glacial deposits north of the moraines discussed here, did not begin until after atmospheric CO2 increased at ~18 ka, marking the onset of Termination 1. [ABSTRACT FROM AUTHOR]

Landform mapping is the initial step of many geomorphological analyses (e.g. assessment of natural hazards and natural resources) and requires vast resources to be applied to wide areas at high-resolution. Among geomorphological objects, we focus on glacial moraine mapping, since it is a task relevant to many fields (e.g. paleoclimate and glacial geomorphology). Here we proposed to exploit the potential of Deep Learning-based approaches to map moraine landforms by exploiting multi-source remote sensing imagery. To this end, we propose the first Deep Learning model to map glacial moraines, namely MorNet. As multi-source remote sensing information, we combine together three different sources: Topographic (Pleiades-derived DSM), Multispectral (Sentinel-2), and SAR (Sentinel-1) data. To cope with such heterogeneous information, the proposed model has a dedicated branch for each input source and, a late fusion mechanism is leveraged to combine them with the aim to provide the final mapping. The performance of the MorNet model is evaluated on several glacier valleys in China in the Himalayan range. This area contains minimally eroded moraines, so they are well-defined and of varied morphology. The behavior of the proposed method is compared to models using individual mono-source models in order to highlight the benefit to simultaneously leverage multi-source information. The use of multi-source data allows MorNet to exploit the complementarity of the three input sources and improve its performance from an f1-score of about 41.6 using a single source to 52.8 using three sources. MorNet provides a first-order moraine map through its ability to identify well-defined moraines. Consequently, MorNet can identify areas likely to contain moraines and intends to be used as a tool by experts to facilitate and support large-scale mapping.

Beryllium-10 cosmic-ray (CRE) exposure dating has revolutionised our understanding of glacier fluctuations around the globe. A key prerequisite for the successful application of this dating method is a thorough understanding of local production rates of in-situ accumulated 10Be, usually inferred from independently dated regional reference sites. For the mid-elevation (Variscan) mountain ranges of central Europe, no production rate reference site has been available so far. We fill this gap by determining in-situ 10Be concentrations in large boulders on moraines and by applying radiocarbon and luminescence dating to stratigraphically younger lake sediments in the southern Black Forest, SW Germany. The dating methods yielded concordant results and, based on age-depth modelling with 14C ages, we deduced a local 10Be production rate. The resulting Black Forest (BF) production rate is ~11 % lower than both those at the nearest reference site in the Alps and the canonical global 10Be production rate. A stronger weathering and snow cover bias and a higher impact of soil, moss and shrub cover at the stud site likely explain this discrepancy. Due to its internal robustness, we suggest applying the BF production rate in future CRE dating studies in Central Europe and for revising existing age estimates which will have crucial implications for understanding past atmospheric circulation patterns. [ABSTRACT FROM AUTHOR]

We show a long-term erosion monitoring of several geomorphologically active gully systems on Little Ice Age lateral moraines in the European Central–Eastern Alps, covering a total time period from 1953 to 2019 and including several survey periods in order to identify corresponding morphodynamic trends. For the implementation, DEM (digital elevation model) of Differences (DoDs) were calculated, based on multitemporal high-resolution digital elevation models from historical aerial images (generated by structure from motion photogrammetry with multi-view stereo) and light detection and ranging from airborne platforms. Two approaches were implemented to achieve the corresponding objectives. First, by calculating linear regression models using the accumulated sediment yield and the corresponding catchment area (on a log–log scale), the range of the variability in the spatial distribution of erosion values within the sites. Second, we use volume calculations to determine the total and the mean sediment yield (as well as erosion rates) of the entire sites. Subsequently, both the sites and the different time periods of both approaches are compared. Based on the slopes of the calculated regression lines, it can be shown that the highest variability in the sediment yield at the sites occurs in the first time period (mainly 1950s to 1970s). This can be attributed to the fact that within some sites the sediment yield per square metre increases clearly more strongly (regression lines with slopes up to 1.5). In contrast, in the later time periods (1970s to mid-2000s and mid-2000s to 2017/2019), there is generally a decrease in 10 out of 12 cases (regression lines with slopes around 1). However, even at sites with an increase in the variability in the sediment yield over time, the earlier high variabilities are no longer reached. This means that the spatial pattern of erosion in the gully heads changes over time as it becomes more uniform. Furthermore, using sediment volume calculations and corresponding erosion rates, we show a generally decreasing trend in geomorphic activity (amount of sediment yield) between the different time periods in 10 out of 12 sites, while 2 sites show an opposite trend, where morphodynamics increase and remain at the same level. Finally, we summarise the results of long-term changes in the morphodynamics of geomorphologically active areas on lateral moraines by presenting the "sediment activity concept", which, in contrast to theoretical models, is based on actually calculated erosion. The level of geomorphic activity depends strongly on the characteristics of the sites, such as size, slope length, and slope gradient, some of which are associated with deeply incised gullies. It is noticeable that especially areas with influence of dead ice over decades in the lower slope area show high geomorphic activity. Furthermore, we show that system internal factors, as well as the general paraglacial adjustment process, have a greater influence on long-term morphodynamics than changing external weather and climate conditions, which, however, had a slight impact mainly in the last, i.e. most recent, time period (mid-2000s to 2017/2019) and may have led to an increase in erosion at the sites. [ABSTRACT FROM AUTHOR]

To further elucidate the Late Pleistocene glacial history of mid-elevation mountainous regions in Central Europe, 10Be cosmic-ray exposure (CRE) dating was applied to moraines in the Zastler Tal Valley in the Southern Black Forest. Periods of glacier recession from moraines in this valley began no later than 16 ka, 15 ka, and 13 ka. CRE ages of moraines in this and other parts of the Southern Black Forest cluster around 17–16 ka and 15–14 ka, thus suggesting a common forcing of glacier recession. Equilibrium-line altitudes (ELAs) during moraine formation were calculated for precipitation reconstruction. Observed spatial discrepancies in ELAs at ca. 15–14 ka are explained best by the size of snow-contributing areas. The reconstructed annual precipitation at the ELA for ca. 16 ka and ca. 15 ka is affected by large uncertainties, representing a wide range from ~50% to ~150% of present-day values. Due to various factors, such as drifting snow, the lower bounds of the estimates appear most realistic, thus concurring with the common hypothesis of less precipitation during the last glacial termination than today in Central Europe. Further research is needed before ELAs of small ice masses can be employed for precise precipitation estimates. [ABSTRACT FROM AUTHOR]

Glacial geomorphological mapping from the southern margin of Skálafellsjökull, southeast Iceland, depicts a topographically diverse mountainside, influencing glacier dynamics, landform formation and glacier retreat since the Little Ice Age maximum in ~1890. The glacial landforms present are typical of southeast Icelandic temperate glaciers, comprising recessional push moraines, including sawtooth moraines, and associated fluting. Study area A demonstrates an abandoned lobe confined by steep V-shaped topography, displaying moraines and minimal fluting, suggesting low preservation of landforms, and changes in glacier behaviour. At study area B, the sawtooth moraine morphology demonstrates changes in the glacier margin as the ice interacted with a series of topographic benches during active recession. The steep-sided valley at study area C illustrates densely spaced arcuate moraines, reflecting subtle changes in ice elevation. This mapping provides a framework for further investigations into glacier retreat rates and the influence of local topography and climate. [ABSTRACT FROM AUTHOR]

We present a 1:15,000 geomorphological map of the Maladeta massif in the Central Pyrenees. Our methodology includes fieldwork, the analysis of aerial photographs from 1956 to 2015, and the use of drone flights from 2020 to 2023. The study area consists mainly of granodiorite but also has outcrops of limestone, shales, and quartzites at lower elevations. The landscape of the Maladeta massif is primarily shaped by glacial and periglacial processes, with fluvial, karstic, and hillslope dynamics manifesting in the lower regions. The assessment of moraine thickness has facilitated the determination of maximum glacier thickness during the Little Ice Age (LIA) and has shown that there is no correlation between ice thickness and glacier extent. After the LIA, the massif experienced a continuous glacier retreat. Currently, only 21.4% of the glacier area observed in 1956 remains. [ABSTRACT FROM AUTHOR]

We review geochronological data relating to the timing and rate of Laurentide Ice Sheet recession in the northeastern United States and model ice margin movements in a Bayesian framework using compilations of previously published organic 14C (n = 133) and in situ cosmogenic 10Be (n = 95) ages. We compare the resulting method-specific chronologies with glacial varve records that serve as independent constraints on the pace of ice recession to: (1) construct a synthesis of deglacial chronology throughout the region; and (2) assess the accuracy of each chronometer for constraining the timing of deglaciation. Near the Last Glacial Maximum terminal moraine zone, 10Be and organic 14C ages disagree by thousands of years and limit determination of the initial recession to a date range of 24-20 ka. We infer that 10Be inherited from pre-glacial exposure adds 2-6 kyr to many exposure ages near the terminal moraines, whereas macrofossil 14C ages are typically 4-8 kyr too young due to a substantial lag between ice recession and sufficient organic material accumulation for dating in some basins. Age discrepancies between these chronometers decrease with distance from the terminal moraine, due to less 10Be inherited from prior exposure and a reduced lag between ice recession and organic material deposition. 14C and 10Be ages generally agree at locations more than 200 km distal from the terminal moraines and suggest a mostly continuous history of ice recession throughout the region from 18 to 13 ka with a variable pace best documented by varves. [ABSTRACT FROM AUTHOR]

The Jostedalsbreen is the largest ice cap in Norway and mainland Europe. Rapid retreat of many of its outlet glaciers since the 2000s has led to the formation of several glacial lakes. Processes causing the formation and expansion of glacial lakes and their interaction with a glacier and terminal moraine have not been widely addressed yet. In this study, we investigate the degradation of the front of the southeast‐facing outlet glacier Austerdalsbreen. Based on a variety of remotely sensed data (UAV‐based and airborne orthophotos and DEMs, satellite images), we analyze the coincident glacial and proglacial changes of Austerdalsbreen and quantify the evolution of this transition zone during the last decades. In particular, we focus on the short‐term evolution of the glacial lake since 2010, we examine the context of a glacier advance in the 1990s, and we report long‐term changes by utilizing 1960s imagery. We discuss the evolution and conditions of Austerdalsbreen compared to other outlet glaciers of Jostedalsbreen. Overall, the glacier terminus has experienced a recession in the last decades. The 1990s terminus advance was more restricted than at other nearby outlet glaciers due to glacier surface debris cover, which is a critical factor for the glacier and lake evolution. However, in the most recent period, since 2012, a distinct expansion of a glacial lake is quantifiable. Since the rates of glacier surface lowering also considerably increased since approximately 2017 and the glacier retreated since the beginning of the 2000s with a clear maximum length decrease in 2015, we interpret the recently formed glacial lake as a contributory factor of glacial changes. [ABSTRACT FROM AUTHOR]

Glacial retreat uncovers large bodies of unconsolidated sediment that are prone to erosion. However, our knowledge of overland flow (OF) generation and sediment transport on moraines that have recently become ice-free is still limited. To investigate how the surface characteristics of young moraines affect OF and sediment transport, we installed five bounded runoff plots on two moraines of different ages in a proglacial area of the Swiss Alps. On each plot we conducted three sprinkling experiments to determine OF characteristics (i.e., total OF and peak OF flow rate) and measured sediment transport (turbidity, sediment concentrations, and total sediment yield). To determine and visualize where sediment transport takes place, we used a fluorescent sand tracer with an afterglow as well as ultraviolet (UV) and light-emitting diode (LED) lamps and a high-resolution camera. The results highlight the ability of this field setup to detect sand movement, even for individual fluorescent sand particles (300–500 µm grain size), and to distinguish between the two main mechanisms of sediment transport: OF-driven erosion and splash erosion. The higher rock cover on the younger moraine resulted in longer sediment transport distances and a higher sediment yield. In contrast, the higher vegetation cover on the older moraine promoted infiltration and reduced the length of the sediment transport pathways. Thus, this study demonstrates the potential of the use of fluorescent sand with an afterglow to determine sediment transport pathways as well as the fact that these observations can help to improve our understanding of OF and sediment transport processes on complex natural hillslopes. [ABSTRACT FROM AUTHOR]

The results of integrated studies of the contents of natural radionuclides (NRNs) 226Ra, 232Th, and 40K and technogenic 137Cs in soils on moraine deposits available from the Bioresource Collection at the Dokuchaev Central Soil Museum are reported. Soils were sampled before the commencement of nuclear tests, during intensive tests, and in recent years. The assayed soils belong to 11 reference soil groups according to the WRB system. Organic, humus (including formerly plow), humus-eluvial, eluvial, and subeluvial horizons and soil-forming rocks were analyzed. The NRNs contents in soil-forming rock amount to 13.4–36.0 Bq/kg (mean specific activity M = 22.2 Bq/kg and standard deviation σ = 7.4 Bq/kg) for 226Ra; 18.9–49.0 Bq/kg (M = 32.1 ± 10.4 Bq/kg) for 232Th; and 417–890 Bq/kg (M = 695 ± 151 Bq/kg) for 40K. In the organic horizons, NRNs are detectable only in the samples of 2004 and 2017 in the amounts of 7.0–43.0 Bq/kg 226Ra (M = 20.9 ± 14.4 Bq/kg), 10.0–21.2 Bq/kg 232Th (M = 14.0 ± 8.1), and 50–620 Bq/kg 40K (M = 291 ± 227 Bq/kg). Narrower ranges and lower mean content (except for 40K) in the humus and eluvial horizons are recorded in the former plow horizon (P) as compared with the AY horizon and in the EL horizon as compared with the AEL and BEL horizons. The NRN content correlates with the particle size fractions in a statistically significant manner. Technogenic 137Cs is detectable only in the recent soil samples. According to its content, the soils fall into two groups. The first group of soils (pits 261 and MLK-4, Lisino education and experimental forestry station) displays a relatively high 137Cs activity in the 0–5-cm layer and a penetration depth of 10 cm. The second group comprises the remaining soils. The cesium content there does not exceed 54 Bq/kg and penetration depth, 20 cm. [ABSTRACT FROM AUTHOR]

Buried mounds have been identified on seismic reflection profiles in the southern Roosevelt sub-basin of the eastern Ross Sea, Antarctica. Since they have never been sampled, the composition of these mounds can only be inferred from their acoustic character. Previous studies have hypothesised that they are buried glacial moraines deposited by ice grounding near the paleo-continental shelf edge, suggesting the beginning of the growth of the West Antarctic Ice Sheet (WAIS) as early as the late Oligocene. This hypothesis conflicts with earlier evidence of the WAIS advance over the central-eastern Ross Sea. An alternative explanation for the origin of the mounds, as mud volcanoes, is formulated here on the basis of seismic reflection profile reprocessing and comparison with other, better studied, mound provinces in the Ross Sea. Shallow drilling is required to verify, which hypothesis is correct, and this has implications for various WAIS scenarios, ice volumes, and thermal rheological modelling. [ABSTRACT FROM AUTHOR]

Generalization of the grain size analyses of the basal Neopleistocene moraines from the sections of coastal outcrops and boreholes in the vast European Subarctic region of Russia and in more southern areas of the Timan–Pechora–Vychegda region showed that the moraines are typical mixed, almost unsorted rocks with similar contents of the gravel–sand, silt, and clay fractions, serving as one of the arguments in favor of their glacial genesis. Their grain size composition is related to the peculiarities of rocks in the glacier bed. It is formed during the crushing, abrasion, and mixing of the glacier-rafted, assimilated, and transported material during its transportation and deposition, which determines variability of the grain size composition of moraines. Consequently, the grain size composition of moraines in combination with other lithological data reflects the pathway and dynamics of the glacier movement. [ABSTRACT FROM AUTHOR]

A warming environment is promoting the thawing process in ice‐rich moraine soils in cold alpine regions, thereby accelerating the formation/development of geohazards in these regions. The mechanism of these geohazards is closely related to the thermal‐hydraulic (TH) coupling behavior of moraine soils, which has rarely been investigated. Here, we conducted a series of bench‐scale TH coupling simulations of moraine soils with ice inclusions in a warming environment. The numerical model was conceptualized from a field survey on the Qinghai‐Tibet Plateau, which consists of a porous medium embedded with multilayer ice cubes with warmer water continuously flowing through it. A TH coupling framework considering ice‐water phase change was established to implement this coupled simulation with different initial ice contents and hydraulic gradients. The simulated results showed phased and nonlinear evolutionary features of temperature, ice content, and permeability for the moraine soil system. Further analyses showed that these complex evolutionary features can be reproduced by empirical formulas, with concise expressions following dimensional consistency and some coefficients having potential physical meanings. The discriminant models of two equilibrium states were finally developed to predict the critical times of structure stabilization and thermal equilibrium of the moraine soil system. This study presents the complex evolution of TH coupling properties of moraine soils, and simultaneously demonstrates that these properties can be predicted and characterized. Plain Language Summary: Due to large‐scale and multistage glacier evolution, substantial moraine soils have accumulated in cold alpine regions. These moraine soils include abundant buried ice in various configurations formed during glacial evolution, and the thawing of this buried ice is accelerating the development of geohazards in these regions. The initiation and evolution of these geohazards are largely controlled by heat transport and groundwater flow induced by ice‐water phase change in moraine soils, but these coupling processes are poorly understood and poorly characterized. Here, we numerically investigated the thermal‐hydraulic (TH) coupling behaviors of moraine soils with ice inclusions in a warming environment. The simulated results revealed phased and nonlinear evolutionary features of the moraine soil system, with respect to heat transport, pore structure, and hydraulic conductivity. We demonstrated that these complex evolutionary features can be well characterized by empirical formulas, and their equilibrium states can be predicted based on the initial ice content and applied hydraulic gradient. These findings and results deepen our understanding of TH coupling behavior for moraine soils with ice inclusions, and serve as a basis for characterizing evolutionary processes of geohazards related to moraine soils in cold alpine regions under climate warming. Key Points: Fully coupled thermal‐hydraulic simulations considering phase change were conducted for moraine soils with separate ice inclusionsEvolution of heat transport, ice content, and hydraulic conductivity of moraine soil was quantitatively characterizedEquilibrium‐state discrimination models were developed to predict structure stabilization and thermal equilibrium of the moraine soil system [ABSTRACT FROM AUTHOR]

Modern permafrost conditions of the Subpolar Urals are characterized by the example of peat bogs of the lateral moraine in the vicinity of Narodnaya mountain area (Polar Urals, Russia). Changes in permafrost conditions due to warming, studied by georadar survey and radiocarbon dating. The depth of thawing in these bogs was also determined by measuring the depth of the seasonally thawed layer and the temperature of the rocks using a thermometer and a metal probe 1.5 m long along a 100 m profile with a step of 10 m. It was found that the depth of the STL ranged from 10 to 140 cm at a permafrost surface temperature of 0 °C. The structure of the peat deposit was checked on a dry section of the swamp using a pit 40 cm deep. It was found that the peat bog is underlain by frozen clay-loam. In the peatland itself, several boundaries of peat and gley accumulation are visible in the layers directly above the underlying loam, which indicates a repeated change in the conditions of peat accumulation at the beginning of warming or the movement of rocks as a result of solifluction flows from nearby slopes. [ABSTRACT FROM AUTHOR]

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Spatial distributions of drumlin fields encode information about ice sheet dynamics. No drumlins formed beneath the most lobate parts of the Laurentide Ice Sheet's southern margin, in South Dakota, Iowa and Illinois, whereas ice lobes to the northeast generally produced drumlins. This pattern may have resulted from northerly ice overriding permafrost. Here we propose a new hypothesis for this pattern by constructing a LiDAR‐based landform map and applying a model of drumlin formation to account for the absence of drumlins beneath the largest of the ice sheet's southern lobes, the Des Moines Lobe. Broad belts of hummocky topography, ice‐walled lake plains, doughnuts and minor moraines, which together cover 90% of the lobe's upland area in Iowa, attest to widespread ice stagnation, as does the lobe's scarcity of eskers. Most stagnation topography is subtle, with insufficient relief to have obscured drumlins that might have formed before stagnation. Minor moraines are crevasse‐squeeze ridges diagnostic of surging, and their ubiquity indicates that during surging, the lobe's soft bed was weak nearly everywhere. End moraines are generally parallel to a minor moraine setup‐glacier, implying that surge‐driven advances were more numerous than indicated by the three major end moraines of the lobe. In the only physically based model of drumlin formation that includes surging, till deposition occurs during surges when effective pressure is uniformly low, whereas drumlins develop during quiescent flow between surges, when basal slip and low‐pressure R‐channels create the spatial gradients in effective pressure necessary to sculpt drumlins by differential erosion. Landforms of the lobe, however, indicate stagnation and down‐wasting during quiescence, without significant basal slip or hydraulic potential gradients necessary for R‐channels. We hypothesize that for the three southernmost lobes of the Laurentide Ice Sheet, surging followed by widespread down‐wasting of stagnant ice prevented drumlin formation, whereas beneath northern lobes it was permitted by climatically‐forced ice advance. [ABSTRACT FROM AUTHOR]

Machine learning is a powerful yet underutilised tool in geomorphology, commonly used for image–based pattern recognition. Analysing new high–resolution (1–10 m) elevation datasets, we investigate its usefulness for detecting discrete geomorphological features. This study develops a machine learning–based method for identifying ribbed moraines in digital elevation data and progresses to test its performance versus time consuming, manual methods. Ribbed moraines share geomorphometric characteristics with other glacial landforms, hence represent a valuable test of our new methodology in terms of differentiating between similar features, and wider for detection of landforms with similar characteristics. Furthermore, mapping ribbed moraines may provide valuable indications of their origin, a topic of debate within glacial geomorphology. To automatically detect ribbed moraines, we extract simple morphometrics from high–resolution digital elevation model data and mask regions where ribbed moraines are unlikely to form. We then test several machine learning algorithms before examining the best performer (K–means clustering) on three study areas in Norway of 15 km2. Our results demonstrate balanced accuracy of 65–75 % when validating versus ground–truth. The performance depends on the availability of high–resolution elevation data in Norway, needed to resolve the spatial scale of the target (10–100 m). We find the method effective at detecting both fields of ribbed moraines as well as individual ribbed moraines. We propose pathways for future implementation of this method on a large–scale and for increasing the detail of information gained about detected landforms. In conclusion, we demonstrate K–means clustering as a promising method for detecting ribbed moraines, with great potential to reduce the time needed to produce landform maps. [ABSTRACT FROM AUTHOR]